here's another good one
people who are just ridiculously biased towards their own team, resulting in some of the following things:
1) they harass article writers and casters for not giving them enough credit/not mentioning some of their good players
2) they misremember scrim results to make themselves look better
3) they pretend it's a big deal every time they win a scrim even though it's just a scrim
4) they pretend it doesn't matter every time they lose a scrim because it's just a scrim
5) they constantly exaggerate the bad circumstances affecting them ("our scout had 80 ping instead of 60 and that's why we lost 5-0!")
6) they constantly try to undermine the bad circumstances affecting their opponents ("so what if they were 5v6? it was only for the last 25 minutes of the game!")
etc., the list goes on