In my case, there are two reasons why I found I could not divorce myself from the 4E forum.
The first is that with the advent of a new edition, discussions about exactly what D&D is suddenly came to the fore. Not that we hadn't had these discussion at EN World before, but they were rarer with fewer participants. 4E made them bigger, longer and occassionally uncut. Obviously, I have some very strong opinions about what D&D "is" and what kind of play D&D supports "best", but so do lots of people. And while the tendency is to believe that more people are troll-ish or spoiling for a fight than not, I think the truth is that for every [you know what, I won't say it] there's 10 other posters expressing their opinions civilly and often eloquently. And since I love D&D and I like talking about D&D, even with people that completely disagree with my preferences and opinions, 4E has been a boon in that way. yes, we've had fights and yes I have let myself get over-heated along with some others, but I honestly believe that some of the best discussions about "the theory of D&D" ever to appear here have come out of 4E (the "Why Worldbuilding is Bad" thread notwithstanding -- I miss those days, Hussar

).
The other reason is that as much as stuff we were getting told was grating on me, flying in the face of my aforementioned D&D preferences and opinions, the fact is I kept waiting for something to get me excited. The idea of "hating" the new edition of my favorite game was not something I liked. Sure, I will always have previous editions, the fact is that most people, most of the people I game with, will move on. I want to like the new D&D because I want to play with those people and I want to play with other D&D lovers at cons and (most importantly for me) I want to keep running both regular and con-style games.
A little hope has sparked here and there. Mearls' comments a couple months ago (reposted from the WotC boards, I believe) were a little heartening. Statements by Orcus that Necromancer was going to keep "old school" play alive in the new edition gave me a little hope. The new monster stat block intrigues and pleases me and makes me think that the actual game, when we finally get to see it in its entirety, will be better than it looks to me based on the previews.
I'm not there yet. I don't like the "anime/WoW" flavour seemingly inherent in the PCs; I don't like the massive reduction in many areas I think of as definitive of "old school" playstyle; I feela lot of meta/implied setting changes are pointless; I think some rule changes are just silly and arbitrary and fixing things that were never broke in the first place. But, I do feel a little better. I do think that if I pay attention and read the previews and discuss them with other people here, whatever decision I come to in June will be an informed one and one I won't regret because I had an opinion and was sticking to it, right or wrong. Without the discussion part, that just isn't possible.
Oh, yeah, there's a third reason: there's been some humdingers and they are just too entertaining to pass up sometimes.