Why is this system so nonsense?

Being on-topic. From the screenshots it would suggest that the OP isn't necessarily doing anything wrong as they are a stronger performer in these sample matches. It is hard to say though when there's a snippet of 3 matches. To hit the infamy tanking zone, you're talking more than 30 losses greater than wins.

Really unfortunate match making has probably contributed towards it.

 

@Miathan, @ForgetIt, @TheAntiSnipe, that's why I think it happens after season begins: some random dude has the bad luck of face top players when they're all with of 4k infamy points on season start, this dude loses a lot of battles, win a little bit, go to 3,5k infamy points. Instead of try to relax and enjoy the game, he starts to make several mistakes due to his anxiety and end up with 3k infamy points before he find the right mindset again.
It is just my opinion but I think that's the reason why so many Nightmare players get to 3,2k infamy points during the season.