A bench clearing brawl is one of the most entertaining aspects of baseball. Don't get me wrong, I don't want to ever see any serious injury to anyone, but a few black eyes and bloody noses build character and inspire team camaraderie. Plus it sets a tone and sends a message to other teams.
Hocky fights are good, but usually are only one on one. Football players hardly ever fight because their season is too short and a three game suspension would be disasterous. Plus they wear too many pads and helmets to do any damage to each other anyway. And with the exception of the "Malice at the Palace" basketball players very rarely come to blows.
Baseball players do it right. And with baseball sometimes being very slow with very little action it makes for a welcome infusion of energy into the game. The results can even turn the tide of a game on some occasions.
I equate it to a car crash in NASCAR. No one wants to see anyone get injured, but everyone is excited when it happens.
There is no coincidence that every crash and every brawl gets prime air time on sportscenter and every other sports show.