My Opinions:
I'm an opinionated person. This is a fact. I can certainly say that, for me, I see fewer posts of interest on ENWorld than I once did. Why, I don't know. Discussions of interest (to me) used to be far more common than they are now.
As for publishers, I haven't noticed a change. Lots of them here, none I've noticed as missing.
(Un)Friendliness of threads? I have seen quite a few, here, that I thought were pretty unfriendly. Some were warned and/or closed by mods, others weren't. I also haven't always found the treatment equal - religion-bashing posts get "overlooked" by the same mod who later closes the thread when someone else jumps in to defend it, for example... Still, overall, ENWorld is one of the friendlier boards I have ever been on, IN GENERAL. (For the rest, there is the Ignore list.)
On cliqueishness, PC, your storyhour thread seems pretty cliqueish, to me... The folks who are/have been in your games are the "cool" people, and the "in crowd". I don't really see how you can claim that they're not... or how it could be otherwise... Yes, there is some cliqeishness, here at ENWorld. Also pretty much anyplace else you go, to be fair...
Darrin, I hear what you're saying/see your point about "I Hate X, Y, Z" posts, but they do seem to have their uses... Seems I recall my own series of "Rants" on why the 3.0 Ranger wasn't being all that he could be, and what was wrong with him... Looking at the 3.5 Ranger, why I'd swear somebody at WotC read those posts, and used most of the ideas therein... right down to making identification of potion types something any magic user could do (a Spellcraft check)... I think there were only about three suggestions in the whole article that didn't get accepted!
Now I can't remember if I offered positive suggestions for change, in most of those posts, but I do remember a lot of negativity! Apparently, somebody (or a lot of somebodies) agreed with me. So I don't know, maybe voicing dissatisfaction with what you don't like can actually have some effect... Then again, I did actually READ 3.0 before I posted, too!...
Anyway, if this post seems negative, ENWorld is still the best board that I know of, for all matters RPG-related, and I don't even bother with WotC or the rest... So I guess the above can be summarized as "I'm opinionated, picky, don't like everything here, but still come here as opposed to anywhere else!" So, consider it a left-handed compliment, if nothing else!
Back to the original point; ENWorld has changed, and become a bit less interesting, to me... No idea why...