Personally, though nobody probably noticed because I was never a real frequent poster to begin with, I stopped coming to the boards about oh, six months ago, and only recently came back, though it's looking more and more like a temporary visit. I'm not really a publisher, as I just made one little software product, but some of my reasons might be the same as theirs, or at least ones they are detecting. Like them or not, here's my reasons for leaving the first time (and probably again soon):
Changing Interests - The fact is, I haven't played D&D/D20/RPGs in about a year now. About the time 3.5 came out was when my interests really started to wane. I'm not blaming 3.5, that's just how the timing worked out. My game group broke up, my books started collecting dust, and for me, the value of the site was lost. It's been a few years now since the revolutionary 3rd Edition came out, so people are probably moving on to other things. My current obsession is
building arcade cabinets.
Same Ol' Same Ol' - This kind of ties into my first point and may be a contributing factor to it. The Slayer's Guide to BLAH, The Complete BLAH, BLAH: A book about BLAH race/class, etc, etc. To me, the good, original ideas have all appeared to dry up. Everything is a rehash of something else, or a sequel of sorts. Give me something original and I'll give you money. I'm sure the publishers can feel that too, at least in their wallets.
The Culture - This one is going to get me beaten down, I'm sure. I know my opinions aren't always popular ones, but the culture around here seems to foster being argumentative rather than holding civil, intelligent conversations. It brings it out in myself too, so I'm not claiming innocense here. It's not everyone, of course, but it seems like differing opinions are immediately followed by antagonistic remarks rather than friendly debate. I can see why publishers would want to stay out of those kind of discussions, as it only serves to tarnish their names.
Block Lists - A popular web proxy filterning service for businesses has rightfully added EnWorld to the "Games" list, so a lot of large companies are now blocking it.
Let the beatings begin!