Presumptuous... the ability of a pokemon makes up just as much how competetive a pokemon is as its stats/movepool/typing. As doug also said a previous post, KNOWINGLY giving it a worthless ability is like giving it shit stats, or the worst typing in the game, or no viable movepool to speak of.
I'm not going to continue on this because I don't like arguing with people, but I still disagree. It may sound like I'm trying to invent hamburger glasses, but for "variety" reasons I don't support giving a good ability to every Pokémon we make. I really think we are capable of making a Pokemon with just a "decent" ability every once in a while without having to drop it in BL or UU ( note that this means I never suggested crappy abilities, that was other people's ideas that I chose not to argue with. I merely suggested "not great" ones ).