Really. Forget the little dance/bow after he rounds the bases. It's the bat flip that has them mad.
Apparently there were some fans that tweeted messages talking about how they didn't appreciate what Brown did and that they wouldn't forget it.
Really? You mean you really don't have anything better to do? Come one man!
The only thing that I can guess is that the fans that are still watching are tired of being mad at the Marlins ownership, and are probably afraid that if they say the wrong thing they will be kicked out of the park (not that the Marlins would have an issue with free speech or anything like that--or have done it before).
But as bad as their team is they can't help but be angry so they figure they might as well take it out on the one thing that they can take it out on--the opponent that just whipped them.