I know exactly what you mean, the dedicated forums always had more specialized knowledge and regulars who were the go-to guys for tough questions.
When everything moved to reddit the specialized, knowledgeable regulars didn't follow and everything became more generalized, discussion of more interesting ideas died and was replaced with shitty memes or attention seeking posts that might as well be spam.

The restructuring of image shack and photobucket also did a huge number to them (all of the good posts and tutorials are useless without pics). Also, most of the forums now all seem to be owned by the same handful of companies. Like they all got bought out by a few groups, implemented new rules and now they're pretty dead.
I miss me forums.