That ain't that bad. Pitcher doesn't like it? Don't give up a bases loaded ding dong. If the other team is to be honest, their frustration is with their own guy and with losing, and they vent their frustration in the name of unspoken norms of the game. If you don't want the other team to gloat, then beat them.
Personally, I'd never bat flip. The runs on the board say it all. But I'm ok with bat blips in certain situations. Game winners, big in-game moments, historical moments. I understand where the emotion comes from.
I'm not ok with them in others: your team is getting their butt kicked and you happen to go yard. Good for you, man. Your team is still getting hammered. Run the bases and sit down. Or if the bat flip comes from the league ego maniac and it's just another "look-at-me moment." I don't understand those kinda guys at all.
What's worse than a bat flipper? Waiting a year to retaliate and using a guy not even on the team when the bat flip happened.
What's worse than a bat flipper? A guy that mashes the ball, walks down first with the bat in his hand, and the ball goes off the wall and the batter (I'm looking at you Puig) gets a single out of it.
What's worse than a bat flipper? A whole lot of other things in the game. Not running out grounders. Moaning and groaning about balls and strikes when the hitter is wrong. Pointing to the sky when you succeed, but not when you fail. Not knowing how to bunt. The DH. "Instant" replay. The Utley slide rule. Hitters and all their "armor." Walk up music. Stuff to do at ballparks other than watch the game. The list goes on.