I'd say no, for all the reasons above and because everyone and their mom is already doing it, not to mention that these "everything" forums tend to have an initial flurry of activity and hype, followed by a not-so-fun long, spiraling decline :p
Starting a forum, even with all the setup done, is hard. Attracting, entertaining, and keeping a user base can be tricky enough WITH a niche to focus on... doing so with no focus is almost going to guarantee a low rate of member retention, post quality, and massive headaches for the people who have to create content and activities for members with skills and interests that are scattered all over the place. Too lazy to scroll and check now but whoever compared this forum to the DeviantArt pixel art forum hit the nail on the head.
Fortunately, we didn't have to "start" Pixelation... while some of us that help run it are founding members, none of us are original moderators or admins. It was already established for us by Tsu and FE long ago, complete with a loyal community with an interest in seeing it succeed. If we had to start from scratch now, I seriously doubt we'd have the same result.
Plus, running a forum isn't all that easy. IMO, all the mods here do a pretty badass job (not patting myself on the back here, in terms of moderating and the day-to-day running of Pixelation the others do way more than I do). It requires a good amount of communication, and since there are often times when there are only a few active moderators/admins on and patrolling, everyone pretty much has to be in agreement on how the forum should be run in order to make appropriate decisions quickly. If you're lucky enough to have an awesome, like-minded community like we do, you'll be able to divert some attention from peacekeeping and mundane rule enforcement into the improvement of the forum as a whole, but it'll always take up a good amount of the time your mods graciously volunteer to your forum.
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