I don't understand why I'd need to switch my brain off when reading it. It's the same as any other series, be it Death Note, Naruto or what have you. To call it dumb or anti-intellectual isn't really accurate, since you don't need your brains when watching or reading anything else either.
As for the fights, that's a matter of taste. I thought they were brilliant. What matters is not how varied the techniques of the fighters are, but how the general flow of the fight goes, which in my opinion is excellent. The only complaint I have is that only the Saiyans were of use, everyone else was essentially useless. As to why Bleach and Naruto are considered shitty, it has nothing to do with the fights as such, but the general poorness of the plot itself. The fights in these shows are more varied than in DB, sure, but that doesn't make them any better. I can understand what you mean by the power thing, it does seem akward that a person has the power to destroy a planet easily, but their fights usually don't do that much damage to the enviroment anyway.