Of course, everyone's "awesome original game that's just round the corner, but isn't worth spending a couple of foot-long subs on". Incidentally, that's a couple of foot-long subs to cover all of your BYOND website needs for a whole year.
It seems like we're all waiting for some flood gate to open and for good developers to start pouring in to save the hub from its current state. If this where to happen, the membership cost would scare a lot of them off if membership was required to make a hub entry. It's easy to say that a feature should be a membership perk because you know what a membership gets you, you understand how BYOND works, and you've decided that a membership is worth the money. You have to think about this like a new user would - they don't know BYOND and don't know why the $18 is worth it.
To solution to this problem ([link]), if it is much of a problem, is to have better searching or keywords. It doesn't look like much of a problem. Searching for "pokemon" does bring up Dragonball Sanctuary (which blatantly stuck "Naruto, Pokemon, Bleach" in its dscription) but it's 20th on the list and follows 19 pokemon games.
There are only two ways of doing that.
A) Make an awesome game.
B) BYOND gets some amazing new feature.
The so-called "purging" would just piss off a lot of people. Pissing people off is the opposite of good marketing. Don't forget how loud that user segment is, now imagine them talking about BYOND off-site. That's a lot of negative word-of-mouth spreading around.