If you blow up at someone during a sports game, there will be real-world consequences for you, eventually you will not be able to play that game at all in your geographic area.

If you yell at people over a computer headset it doesn't matter what they think of you, you can simply move on to the next group of people. Very rarely (mostly at the very top levels) does reputation matter. And at the end of the day you can simply name change and escape your rep.

Interpersonally the stakes are orders of magnitude lower in video games than in RL.