Is there a proper term for this sort of development? You see it a lot with artists that get big off of fanart of existing IPs and let the followings go to their head. I can't think of too many other examples off the top of my head, but the process goes something like...
1: Get big by doing something not connected to your personality.
2: Start putting more spotlight on your personality, rather than what got you big.
3: Be surprised by the backlash.
I haven't watched them in a while but iirc the DTRH videos are pretty solid. But also Knudsen's personality in no way, shape, or form, is attached to them. He's makes a documentary and he narrates it. He didn't get big off of his personality. So of course the average viewer isn't going to think positively of him going off to play vtuber instead of continuing the series. They were never following for his personality, and a vtuber is a highly personality focused thing. It's literally not what anybody signed on for lmao.