I think we can legitimately ask what social forces are at work in creating such a disinterest

Fair enough, but again it drags the argument back into tying disinterest with active disapproval or worse, and I find that a slippery slope. If someone says "I am not interested in (group)'s issues" I will privately label them as a jerk, but that's the end of what I can assume about them. I am having difficulty finding anything unnaceptable about such a stance; vexing, yes, irritating, yes, worrisome, yes, but not unacceptable.