@quadsword To be clear, most people play competitive because they're intending to take the game more seriously. By definition, people will have heightened expectations, emotions, and criticism. That doesn't make competitive modes bad, it just means competitive modes might not be for you.
As I recall, in Ins2 they tried to haphazardly appeal to the competitive scene, but at the same time neglected the real needs of the both the competitive and casual scenes as a whole, and the whole thing fell apart into what we have now--the same ~400 people playing Ins2 on the same dozen or so servers.
You've placed the blame for QC's failure on the devs, when it sounds more like a failure on the part of the community. It sounds to me that the community was just a toxic shit-show, if it was as you've described it, and no developmental TLC was going to fix it. For example, League of Legends has had a significantly competitive community for years. The game has been balanced around competitive play, for the most part. And it's popular, casually and professionally. I can't fucking stand it, though. The community drives me up a wall, for the exact reasons you mentioned about competitive players, but I encounter it in the most casual game modes.
I think you might have gone a little overboard on your criticism of competitive modes as a whole based on anecdotal experience, and the overall toxicity of gaming communities in general. I don't blame you, it's easy to come to that conclusion. But as someone who's been in competitive gaming scenes in some capacity across 5-6 popular titles, I can tell you that most people who rage and freak out at their teammates are not representative of the community at large, and are often the rejects and pariahs of the true competitive scenes.