Well, it's fine if you don't think the U.S. Is the best, just don't make a point about it. It's not so much that Americans don't think America has faults, we just mostly love our country and take offense if you criticize it the wrong way. I love France but it certainly has its fair share of problems, for example, but I don't go around arguing with The French if they say they love France and it's the greatest place. It's just non-productive.
Also in SF you'll get a bunch of self-hating people who haven't traveled much who think the U.S. sucks, just like in Alabama you'd get a bunch of irrationally pro-America people who haven't traveled much and don't see why the U.S. can suck with certain things.