I really don't see what benefit separating the streams accomplished. It doesn't stop fights. It doesn't make imgflip easier to use, or more fun.
The one potential benefit is maybe certain memes are easier to find (eg if you're looking for something to post on another site), but since there was already a Search function, that's pretty moot.
But apart from that, it seems like they made the site more convoluted, more difficult to use, and more prone to users flagging stuff from other users for being in the "wrong stream" (just ridiculous), all because a vocal minority couldn't just scroll past memes they disliked, like everyone else was doing.