people who watch those automatically assume that Bleach and Naruto are the best anime ever, and have never heard of the godsends that are Zero no Tsukaima, Vandread, and pretty much any other obscure anime.
Ah, the awesomeness of unpopularity. I don't doubt that many animes that are good are not so widely known, but that's a bit of a silly thing to say. Anime elitists!? What are we coming to?
That being said, I like Bleach over Naruto because the soul society story arc was amazing, while Naruto never really did anything to me and never hooked me into it.