@ManitouRyan
I think that's definitely part of it, but unfortunately (and I'm only hazarding a guess since I'm not on BS, and barely on here anymore) I'm also of the opinion that a lot of "bigger" accounts miss the Internet points that #xitter offers up (a LOT of which comes—directly and indirectly—from bot accounts/trolls).
So even people who aren't outright Nazis will stay/go back to #twitter because they want the "engagement" numbers...and because #clout is a helluva drug.