The only thing more annoying than fairweather fans are guys who get on their moral high horse and act like they're above it all
You see this shit talking behavior in message boards of EVERY single sport. You see tons of people on the streets wearing Cleveland Cavaliers gear but you'll still have hordes of other fans celebrating every time Lebron loses in the finals. Sports fans have always been irrationally passionate and opinionated.
It will continue happening forever, but guess what, Liddell, McGregor, Fedor, Aldo, Lebron, Tom Brady, etc. will still have people coming up to them asking for their autographs and telling them how much they love them. The online shit talking isn't really hurting anybody so you can drop the jaded fan act