The problem is that allegedely 80% of Bytecoin was premined by its creator, so it may be extremely centralized. Aslo, Monero is basically a fork of Bytecoin.
That's the thing, everybody always talk about the "premine", but as I understand it, it is very hard to actually provide concrete proof that it happened. I've read the evidence out there and the thread that exists here on Bytecointalk but it just seems like a bunch of Monero fan boys who want to shit talk Bytecoin because he competition to their favorite coin is automatically the devil. Again, that could just be my opinion but that's the way all of the discussion look to me.