I think it's because of the "America's Team" thing, which is pretty silly.
It's not that they have a dominating record comparable to the baseball Yankees, which is why many hate the Yankees, or like Apple, which is why many hate Apple.
It could be cheerleader envy, though.
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See, this is why we can't have nice things. - - smarkinson
Where else but the internet can a bunch of cyclists go and be the tough guy? - - jdon