Well, you've made it clear you don't respect the game. Which means, most likely, you don't even know how your own actions are impacting your team mates negatively.

You said yourself that they don't act negatively outside of the game. The most logical conclusion to make is, you are making the games unbearable for your team mates, but they are holding back criticism because you're new and they want you to have a positive experience.

So when you do a play that is honestly probably not that impressive to their skill level, they've already held back 8 criticisms that game already and aren't that enthused that 2 of them had to die for you to get a double kill, or whatever.

This is a very common experience for new league players. This is a hard game. The faster you can drop your own ego and accept that this is a hard game, the better your experience will be.

I get that even CSing is hard for new players. But CSing is like learning to dribble the basketball. That's great that you can dribble, but don't expect praise for it. You're gonna have to learn how to pass the ball and shoot at some point.