Jon just strikes me as being the way he is because not enough people in his life have decided to tackle him on certain stuff, and its come as a detriment to his character. Like when he pretty much tells Arin not to crit DKC because its one of his faves and sort of projects this porcelain baby bird persona that could shatter if ever faced with too much criticism. Its never healthy to a person, but because people never want to be "that asshole", nobody ever really steps up to the plate. Turns out you didnt like DKC as much as you thought Jon, welcome to realising nostalgia is a cloudy agent indeed.
Add to that a fanbase coalescing into almost a secondary shell around this beloved baby bird to protect it from everything else (Knux-Future in this very topic for instance with repeated Y'ALL ARE THE REAL GRUMPS HURRRRR rhetoric) and you get an insular as hell web-series that will only get worse, not better.
I loved the start of Game Grumps, but maybe because of them trying to force too much out and because Jon's terrible game choices have taken precedent (theres no way we'll tire of ALL THE DKC GAMES BACK TO BACK!!!!) the show has lost a whole fuckload of lustre.