Yup, completely clean slate here too, and I see the exact same thing.
You are stuck in a game with people, some of which are already hostile at the very start of the game, and you are required to experience their hostility for 30min to an hour at a time.
One mistake can result in you being called names for the rest of the game, and people have been banned for merely standing up for themselves, you can't fight back. Fighting back is bannable.
So you are forced to 'bottle up' your feelings, as you have no way of expressing them, or defending yourself.
Any psychologist, including the former head of customer service that left Riot when they changed their policy on bans and punishment, will tell you that this harbors toxicity.
So yes. You are 100% correct.
That said, they know it. They've been told it. The old forums actually had a VERY LONG stickied post where they detailed the reasons why punishment was the improper response.
They deleted that stickied post.
The old community rep quit shortly thereafter.
Now the community is many times more toxic than it was back then....
And Riot is making a ton of $$$$ off of it.
Banned accounts = new smurf accounts.
New smurf accounts = people buying skins they already bought at one point.
Rinse. Repeat.