It may be noted that Stirner's criticism of "Communism" (or "Socialism") is directed specifically towards certain strands of "communism", especially those which were prevalent in Stirner's time...

Stirner was not against socialism or communism. In Stirner's own words, he was “not against socialists, but against sacred socialists” (see Stirner's Critics)

It could be argued that he was in favor of a sort of anti-work communism; that, his idea of the union of egoists is especially compatible with such an association, etc.

“In the last analysis, what is the significance of life? If we divide mankind into two great classes, we may say that one works for a living, the other does not need to. But working for a living cannot be the meaning of life, since it would be a contradiction to say that the perpetual production of the conditions for subsistence is an answer to the question about its significance, which by the help of this, must be conditioned. The lives of the other class have in general no other significance than that they consume the conditions of subsistence. And to say that the significance of life is death, seems again a contradiction.”

— Søren Kierkegaard,
Either/Or (Vol I) (chapter 1)

The industrialist was horrified to find the fisherman lying beside his boat, smoking a pipe.
–  Why aren’t you fishing?, said the industrialist.
–  Because I have caught enough fish for the day.
–  Why don’t you catch some more?
–  What would I do with them?
–  Earn more money. Then you could have a motor fixed to your boat and go into deeper waters and catch more fish. That would bring you money to buy nylon nets, so more fish, more money. Soon you would have enough to buy two boats, even a fleet of boats. Then you could be rich like me.
–  What would I do then?
–  Then you could sit back and enjoy life.
–  What do you think I’m doing now?

from Timeless Simplicity by John Lane

Timeless Simplicity: Creative Living in a Consumer Society by John Lane (illustrations by Clifford Harper)

It is with morality [Sittlichkeit] like it is with the family. Many people break with morals [Sitte], but with the conception of ‘morality’ it is more difficult. Morality is the ‘idea’ of morals, their spiritual power, their power over the conscience; morals, on the other hand, are too material to rule over the spirit, and do not hold captive a ‘spiritual’ man, a so­-called independent, a ‘freethinker.’*

* Freigeist : literally ‘free spirit’; can refer both to freethinkers and to libertines.

Because faith in Protestantism became a more inward faith, the enslavement has also become a more inward enslavement; the person has taken these sanctities into himself, intertwined them with all his hopes and endeavors, made them into a ‘matter of conscience,’ prepared from them a ‘sacred duty’ for himself. Therefore, what the Protestant's conscience cannot get away from is sacred to him, and conscientiousness most clearly defines his character.

Protestantism has actually made the human being into a ‘secret police state.’ The spy and lookout, ‘conscience,’ monitors every movement of the mind, and every thought and action is a ‘matter of conscience,’ i.e., a police matter. The Protestant consists in this frag­mentation of the human being into ‘natural desire’ [Naturtrieb] and ‘conscience’ (inner populace [Pöbel] and inner police). Biblical reason (in the place of the Catholic ‘Church reason’) is considered sacred, and this feeling and consciousness that the biblical word is sacred is called—conscience. With this, then, sacredness gets ‘shoved into one's conscience.’ If one doesn't free himself from conscience, the consciousness of the sacred, he can indeed act unconscientiously, but never without conscience.

The Catholic finds himself satisfied when he fulfills the command; the Protestant acts to ‘the best of his knowledge [Wissen] and conscience [Gewissen].’ The Catholic is in fact only a layman; the Protestant is himself a clergyman [Geistlicher]. This is precisely the progress of the Reformation period over the Middle Ages, and also its curse: that the spiritual [Geistliche] became complete.

— Max Stirner, The Unique and Its Property

Apply this same critique to the Protestant work ethic and the capitalist morality of work influenced by it, how it transforms the worker into a self-policing slave.

The morality of work is the morality of slaves, and the modern world has no need of slavery.

(Bertrand Russell)

"If you work for a living, why do you kill yourself working?"

— Tuco from The Good, The Bad and The Ugly, 1966

“Let your competence take effect, collect yourselves, and there will be no lack of money — of your money, the money of your stamp. But working I do not call ‘letting your competence take effect’. Those who are only ‘looking for work’ and ‘willing to work hard’ are preparing for their own selves the infallible upshot — to be out of work.”

— Max Stirner,
The Ego and Its Own (Second part. II. 2)

“A child free from the guilt of ownership and the burden of economic competition will grow up with the will to do what needs doing and the capacity for Joy in doing it. It is useless work that darkens the heart. The delight of the nursing mother, of the scholar, of the successful hunter, of the good cook, of the skillful maker, of anyone doing needed work and doing it well — this durable joy is perhaps the deepest source of human affection and of sociality as a whole.”

— Ursula K. Le Guin,
The Dispossessed (chapter 8)

“Society has decreed a welfare as the ‘true welfare’, if this welfare were called enjoyment honestly worked for; but if you preferred enjoyable laziness, enjoy­ment without work, then society, which cares for the ‘welfare of all’, would wisely avoid caring for that in which you are well off.”

— Max Stirner,
The Ego and Its Own (Second part. II. 2)

The refusal of work and authority, or really the refusal of voluntary servitude, is the beginning of liberatory politics. Long ago Étienne de La Boétie preached just such a politics of refusal:
‘‘Resolve to serve no more, and you are at once freed. I do not ask that you place hands upon the tyrant to topple him over, but simply that you support him no longer; then you will behold him, like a great Colossus whose pedestal has been pulled away, fall of his own weight and break into pieces.’’

La Boétie recognized the political power of refusal, the power of subtracting ourselves from the relationship of domination, and through our exodus subverting the sovereign power that lords over us.

— Michael Hardt & Antonio Negri,
Empire (2.6)

If you can no longer believe a thing, you do not have to force yourself into faith or to busy yourself lastingly as if with a sacred truth of the faith, as theologians or philosophers do, but you can tranquilly draw back your interest from it and let it run. Priestly spirits will indeed expound this your lack of interest as ‘laziness, thoughtlessness, obdu­racy, self-deception’, and the like. But you just let the rubbish lie, notwithstanding. No thing, no so-called ‘highest interest of mankind’, no ‘sacred cause’ is worth your serving it, and occupying yourself with it for its sake; you may seek its worth in this alone, whether it is worth anything to you for your sake. Become like children, the biblical saying admonishes us.* But children have no sacred interest and know nothing of a ‘good cause’. They know all the more accurately what they have a fancy for; and they think over, to the best of their powers, how they are to arrive at it.

— Max Stirner,
The Ego and Its Own (Second part. II. 3)

Certain ways of life, especially leisureliness and contemplation, are said to be marked by ‘self-sufficiency’ (Aristotle). Here there is a double connotation of not needing much from others to carry on such a life, and of the life itself having the character of finality. Both connotations suggest forms of independence. Not needing much from others means being independent of them. And ‘finality’ implies that the activity of thinking, or, more generally, of being leisurely has intrinsic worth. Thus the leisurely person is independent in the sense that the value of his leisure does not depend on any consequence it may have, for example, the consequence that it restores his energy for the next day’s work.

— Lawrence Haworth, Autonomy: An Essay in Philosophical Psychology and Ethics

“A master in the art of living draws no sharp distinction between his work and his play, his labour and his leisure, his mind and his body, his education and his recreation. He hardly knows which is which. He simply pursues his vision of excellence through whatever he is doing and leaves others to determine whether he is working or playing. To himself he always seems to be doing both. Enough for him that he does it well.”

— L. P. Jacks, Education Through Recreation (chapter 1)

“But what is work, and what is play? When you listen to a master performing great music on the violin, or watch a Pavlova visibly enacting the music of the human body, arts acquired by years of the sternest discipline, is it work, or is it play that you are witnessing? It is both. Work and play have joined hands. Labour and leisure have combined their natures. Art and industry have become one. The highest kind of work and the highest kind of play are indistinguishable one from the other. They are two names for the same thing.”

— L. P. Jacks, Education Through Recreation (chapter 2)