Honestly, the co-workers and his boss were right: MC is really just a narcissistic punk.
A game should always be fair and challenging. If the game that he made was just plain impossible or at least so frustratingly hard that the entire gamerbase started a shitstorm, then it was a bad game. And I am pretty sure his collegues didn´t went from praising him to shitting on him in a matter of moments. Pulling a guy who ruins the players fun from development was the right decision. And even his bosses "It will always be the same"-line (that we were clearly supposed to disagree with) is quite spot-on: As long as MC doesn´t realize that he is at least partly at fault, he will keep making the same mistakes.
But fortunately for him, he is now in the only position were making a frustratingly unbeatable "game" is actually the goal of his job, so I doubt he will undergo any character-development in this regard.
Just another egdy revenge-isekai. Bookmarked, I can´t wait to see how dumb it gets.