I can't say that I've seen a lot of this. In my experience people are generally quite receptive to constructive criticism after a loss, as long as you're the least bit diplomatic about it. Excepting people who are clearly just there to troll, I've really only rarely encountered players who wouldn't take advice in the middle of a game, as long as it's not like: "hey [slur] you're making us lose stop being [slur] and git gud".
On the other hand, what I see all the time are huge assholes who are I guess too socially or emotionally stunted to recognize that they're huge assholes. These people appear to genuinely believe that they are politely offering constructive criticism, and for some reason also that they are not garbage humans.
This is really just Dunning-Kruger, I expect. People with no ability to get good results interacting with others are incapable of telling that they're bad at interacting with others. This is compounded by another manifestation of something like the Dunning-Kruger effect -- often it is the case in competitive online games that people who ain't shit nevertheless think that they're the greatest. The only reason they're not Master tier is because matchmaking keeps screwing them by giving them horrible teammates. What you run into a lot is that someone who is mediocre at best relative to the rest of the team gets incredibly angry at other people on the team, who often actually are doing what they should be doing, but thinks of themselves as trying to responsibly "captain" their team and help their teammates play better.
When I used to play lots of League of Legends, sometimes on the forums one of the staff would have people request to have their bans reviewed. This was always fascinating. People would give every impression of genuinely feeling that their ban was unfair. They would tell their side of the story, how really all they were doing was responding civilly to someone being a troll or a jerk, or how they were only trying to help their team win, etc. And then the Riot staffer would produce chat logs showing them to be terrible people. This happened over and over again. And people didn't learn. They continued to genuinely believe that their ban was unjustified. And it's not like they were just misremembering what happened. Even after the chat logs would get posted these people would argue that, no, that guy really was being a [slur] and you have to do this or they'll never learn and you can't baby these people or else pretty soon we'll be calling teachers toxic for giving kids a C.
So I gotta say, I don't think you make a convincing case and I come away feeling that it's pretty likely that you're a terrible person to play with and a pretty big jerk. To say that online gaming suffers from games having too much of a "care bear" attitude is frankly so disconnected from reality that I am not sure how you function in day to day life, and this should be obvious to all but the most socially stunted people who spend any real time playing or watching streams of high-level games in something like League of Legends. I would ordinarily be somewhat more diplomatic in my criticism, but, well, you are asking for it.