Bitcoin does have some stable backings. Most of the merchants only accept Bitcoins but not alt coins. Alt coin's price are too unstable, they can crash any moment. I believe most people understand Bitcoin better than any other alt coin.
I think that understanding can change pretty quick, though. Just takes a few implementations and people will accommodate something new.. and of course since most people don't and will never have much idea about how digital currencies actually work, it shouldn't really matter. But really, in all likelihood something will get more momentum in the next few years, very possibly sth which doesn't exist as yet but which uses existing tech. I guess cryptonote coins why not, but scrypt could still get a look-in, nothing wrong with a spot of doge in my book (still).