I don't know. I've been wondering lately if it forums are worth it. Please note the plural. Part of it's feeling like there's just not a place to fit in. A big part of it is a sense of looking over your shoulder, wondering if what you post will be some sort of "violation." If you feel like you're always walking on eggshells, then what's the point? Can we even make that observation?
Like the ads. How far can we talk about them? The ads don't bother me because they were so annoying, I use a certain browser where I don't see them. Had the ads been less intrusive, I might not have bothered. Where I might have seen the occasional ad, now I see none.
Will pointing that out end up with the post deleted, the thread locked, and myself banned? Don't know. At the moment, don't really care.
Maybe that ambivalence is the answer to the question: People are leaving forums because they no longer enjoy it.