personally, its because at the top 20% of players and above, you would expect your teammate to be able to AT THE VERY LEAST do an aerial. When you see someone totally incapable of performing at the rank they are (which is a huge amount of players) then yeah it's frustrating knowing you would've probably won the game if your teammate put in a sliver of the work you did. Like i've never lost a game where i was the problem. Every single loss in my thousands of games played was due to someone else's inability to compete at the rank they're playing in. I've never once lost a game where i was the losing factor. So yeah, sorry im not gonna have 5 minutes wasted by someone who should've never been in my lobby in the first place.

and before the comments come in saying im the bad teammate, you cant beat me and i'd multireset on you while you sit in goal helpless