BM'ing enemies during a game is good, agree or disagree
First of all, let's talk about the difference between harassment and BM, it's an important distinction to make for my argument. BM is to gloat/put down players in an effort to get in their heads. Harassment is just BM that goes too far. Where do we draw the line? I draw it at repetitive, targeted, and unwnanted BM.
One thing to point out is that all harassment is BM, but not all BM is harassment.
Here's an example of BM. "Uninstall, loser"
It'd be harassment if it or something similar is repeated after someone makes clear they don't want to engage in that way
Now that I've got that out of the way, I'll try to explain why BM is good. It increases the stakes of the game temporarily and thus people try harder to win, and provides a common enemy for the team to unite against. In a ranked game, you've got 20 lp on the line, but when someone calls you or your teammate a loser it's personal. Now you're trying to win for LP, and to shut up the guy who is BM. Your whole team is thinking "fuck it, no ff now, we gonna lose but I won't lose lying down."
It's like someone plugged a pair of batteries into the team, they go quiet and focus. Then when they win, they BM the fuck out of the enemy player back. If they lose, they made the enemy team respect them by not giving up, and by making the enemy team work for a win.
Often when teams BM each other, it's a healthier outlet than fighting within a team. Either way you're frustrated, but when people BM enemies it paints a target on their back and your team unites against a common enemy. You want to fuck up the guy who says your top sucks, more than you want to fuck up your top who sucks.
This is my experience playing this game and other sports. If you saw something different please say so.