He said "I will gladly look on how you'll drown in bog of development" which isn't jaded. He is actively cheering the dev's and the game's misfortune. That's 100% hostile, and driven purely by the fact that the developer would prefer to use their own skills to develop the art assets instead of a machines. They didn't even disparage AI art, they just said they didn't plan on using it!
Also "drawing takes time therefore it leads to development hell" isn't an objective truth, not at all. Drawing your own art will extend time compared to stealing it yeah, but that doesn't automatically mean development hell. That's has a specific definition encampassing many issues like: scope creep, changing priorities, student syndrome, spaghetti code, shifting scope, and more. Saying drawing means development hell is like saying driving cars means car accidents. You can drive a car and never have an accident, and you can be involved in an accident whilst not driving cars. I've seen games with AI generated assets also enter development hell. And games with no art assets also face the same problem.