I wish I understood this aura of dislike myself, because to be perfectly honest, they're some of my all-time favorite KOF characters. Even when '94 came out, I liked them. And when they got some cool new moves and all that extra nice looking animation in '98, they were even better. I think what it is, and this is just theory on my part, is that SNK made them not to be taken seriously. Of course, the problem is, people automatically associated "nonserious" with "lame", and that's where the dislike started.
I'll give you another example. Think about the World Heroes characters. It's obvious that a lot of "tongue in cheek" design were put into them. This isn't a bad thing, it gives those characters their own special look and charm. But when you drop that same idea into a "serious" fighting series like KOF, it may not go over well.
That wasn't a slam to any of the WH characters mind you, just the closest comparison I could think of. For me the cool thing is, you're not supposed to take the USA Team seriously, but once you learn their moves and get into their styles, you take them seriously anyway.
Did anybody get to see any of the Hong Kong KOF '98 comics? Team USA were given boss status in the story, and how they were portrayed, it would make anybody think twice when viewing them again. Brian in particular is portrayed with glowing red eyes when he pulls off special moves, and fights five characters at once. Heavy D fought four or five characters, and Lucky went one on one with Joe Higashi, and that fight went for several issues.