By "inherently individualist" do you mean that Lisp programmers tend not to work in teams? Or just that there aren't many of them, so they tend to be thinly scattered and thus isolated?

My current pet theory is that only a minority of people feel comfortable thinking in s-expressions. For the majority, trees with many levels of nesting aren't a natural medium for expressing their thoughts. (I don't know why this would be, but it's worth pointing out that human language has a very low tolerance for nesting (in fact you almost never see it go beyond level 1)).

I know two very good programmers who gave Lisp a good try and just don't feel comfortable in it. So I don't buy the inferiority argument either. Interestingly, both of those guys strongly prefer Smalltalk, which is arguably as close to Lisp-with-all-those-trees-unwound as anyone has got.

Edit: I'll add that if the nesting theory is correct, I feel lucky to be in the minority that finds it comfortable to build programs that way... what I'm able to do in Lisp far outstrips what I was able to do before.