I chose a general purpose forum with no other current candidates because it is a compromise. You still get a forum that organizes ER well, and does not support the argument that people may use of favoritism, since the bar will be set for games that truly do need organization on the level of ER. Sure, it may not come for years, the point of this is to have the greatest acceptance from both sides.
But there's one more problem with that compromise that just occurred to me. Imagine this: ER has existed for two years, more or less, and gets to be the first and only game to move to a subboard that, in all but name, is its own. Immediately after that, a bright new mind conceives a wonderful idea for an RTD and starts to diligently work on it. Two years later, this RTD has grown to be as large as ER, and really needs some help with its organization. It needs to go into a subboard.
Luckily, somebody has thought of this eventuality by making the ER subboard technically an ER-sized game subboard. So it gets shunted into there next to the possibly much, much larger four-year-old ER, where it is now a minority presence and likely will be for years to come, stuck amidst a sea of ER subthreads.
Now, I don't think the GM of this purely hypothetical game will be very happy about that. Hence why a dedicated ER subboard is, in my opinion, the more honest and desirable alternative.
Yes, so much worse to have it drowned out by half a dozen threads of a single game than hundreds of little games.
There are arguments against the more general subboard, but that isn't one of the stronger ones...
(Also, didn't ER celebrate its FIRST birthday not long ago?)