Why do people despise Miami Heat fans? Just because their teams are worse and won't win titles?

Let's face it, the Heat had almost no fans until a year ago. Now there are many fans all of a sudden. But why is that bad? Who wouldn't want to root for the best team in the league that will win many titles? Before I was a Spurs fan, then I kind of liked the Celtics and now it's hard not to be impressed by the Heat. I mean they have 3 all-stars on their team. Many people would make the case that 2 of those players are the best players in the league.