Yeah your point is very clear.

Currently there is no modern fighter that comes close to fitting your idea of an "all american hero"

So you are left with fantasy "what ifs"

Yes Pavlik would have been a bigger star had he been more talented. He wasn't. So it's impossible to gauge what his popularity would have been in this current time.

If a time comes when an "all american hero" becomes as brilliant, popular and famous as Floyd Maywether, then you can consider your theory about nice guys was correct.