You're seeing things way too much in their logical extremes. From what I'm reading, you seem to think the following:
Any criticism is good criticism, and without criticism, you're just being lauded for fucking up.
That's...Not it. At all.
For starters, those instances of "uninstall", "get good", "fucking trash", etc - those are destructive criticisms. Their only goal is to insult and harm, and there is nothing to be gained from them. If those somehow helped you, it was more than likely through negative reinforcement and your own desire to prove them wrong. Their criticism was still terrible.
Second - just because you willingly took criticism from any source, and managed to learn the game through volition and determination, doesn't mean everyone else will. Be mindful of others, and don't start bearing down on people just because you think they'll improve if you get on their case. Odds are, they won't.
And a part of that unwanted criticism helping nothing would very likely be - as I said - it being non-constructive. If you just criticise with no effort made to point out possible other directions to take, and your goal is to help them get better, you are failing, miserably.
But what if no one said when I first started.
You'd likely still learn, perhaps at a slower pace. Perhaps at an equal pace, even.
What if everyone applauds and cheer me when I make a mistake...
They won't. The thought of it alone is asinine, and that you propose it as though it's the only alternative to criticism is even moreso.
There is no failure since every move and decision are right and people are being positive, hence, I cannot get better.
No, there are still failure states. Just because people are being positive or neutral doesn't mean you can't still fail.
Non-social failure states include:
- Champion Death
- Turret Death
- Inhibitor Death
- Match Defeat
And there are also non-social, non-failure states you can use to determine your growth, like comparing your score to the enemy or your teammates.
But to say "nobody's criticising me so I can't get better" is ignorant, asinine, and just plain wrong. Improvement is an act of volition, and you can only improve if you see room for it and act on it. It doesn't exclusively take criticism to spark it.
Everyone is a winner.
Even when that big, red banner coalesces on the screen with the announcer reading "DEFEAT"?
No. Like I said - even without people telling you "you suck", there are lots of signs to tell you that you can improve.