It seems to me that there's a small fraction of people who are into this stuff that are really doing this thoughtfully and for the right reasons, and that the majority really are either pursuing an aesthetic or using this or other social causes as sort of a prop or a distraction. I suppose this could vary based on where you're at, but I've met few people in the Midwest who were into this stuff that were not shallow and/or neurotic.

At the same time, that's an incredibly stupid argument to use to dismiss what is being done. The positive effects you mention happen regardless of the motivation of the individuals, and the people that start these trends seem to be the ones who really care.