The problem with the lisp community was not that it contained people like this and Erik Naggum, but that they were celebrated. We all have flaws, which is no shame, provided we know they're flaws.

Maybe lisp's expressivity confers an advantage, but like a smelly bum shouting alcoholic abuse at passersby with secret superpowers, you have to wonder if it's worth it. Some people think the greatest strength of homo sapiens is our intelligence - but history suggests that it is our ability to cooperate (to share insights, build on them and to specialize) that is our real talent - our collective intelligence. Lisp's community celebrates individual, non-collective intelligence; people re-implement work themselves rather than reuse others' work.

It's not just the "community" though, there are also technical factors: the purpose of much of Java's "ceremony" is to facilitate re-use, especially in larger projects. Lisp's prototyping strengths are reuse weaknesses - a natural trade-off.

I like esr's point that lisp gives you additional perspectives in other languages - though a mathematical approach, which lisp models in some ways, gives this more strongly IHMO.

EDIT I invite rebuttal of the specific points raised in this comment.