I agree with most of the posts. There's nothing wrong with SA and it is one of the first non-BMC beers I ever drank and enjoyed. Still today, Sam Adams serves as a good back up beer for me when I'm out to dinner or someplace random that doesn't have anything else I would prefer.
But, I don't think there's anything wrong with BMC either. When I'm on a fishing or rafting trip, sweating in the middle of summer, and someone tosses me an ice cold Miller High Life I'll gladly drink that too. It just isn't what I like most of the time, and I'm sure as hell not going to risk breaking a bottle of homebrew or wasting money on a can of craft brew that gets tossed overboard, stepped on, or warmed up in the sun.
To me there is a time and place for almost any beer, it's just that the time and place for BMC doesn't occur very often for me.