If it's worth saying, but not worth its own post (even in Discussion), then it goes here.
After several attempts at providing a direct answer to this, I find that I am currently unable to.
The term "wrong" here confuses me more than anything. What's the point of the question?
My comment is about how the need for closure is suboptimal for both the individual and the society, and how reality doesn't necessarily fit with a human's inner narrative expectations on this subject.
If you're asking about why generic society would scorn and negatively perceive the notion of it being selfish, it's because it's socially accepted and socially expected in most cultures that individuals must not be selfish. The details of that probably belong in a different discussion.
The term "wrong" here confuses me more than anything. What's the point of the question? My comment is about how the need for closure is suboptimal for both the individual and the society
Let me rephrase the question in your terms, then. Why is the need for closure suboptimal? What are you optimizing for?
Consider hunger -- the desire to eat. It is "extremely selfish" and "suboptimal for both the individual and the society"?
Consider the need for solitude. Consider the desire to look pretty. Consider the yearning to be loved. Are they all "extremely selfish" and "suboptimal for both the individual and the society"?