Sounds to me like he should be given veto power in projects he gets hired on to. I didn't mind the Witcher because I hadn't gotten very far into the lore myself and didn't see how much it had gone off the original path, but I'm kinda tired of producers and directors taking an existing story but then changing huge parts of it.
There's nothing wrong with telling your own story but enough with the bait and switch ones. Give it your own name, don't leech off of the name recognition of already loved stories.
I personally am not a rabid Witcher book fan — I swear, some folks think they are the best literature out there and they very much are not — but in their quest to make Yennefer a more fleshed out character, they screwed up her motivations and priorities. She’s supposed to be like a mother to Ciri. I did not watch season 3 but it was not looking good for their relationship at the end of season 2.
They did try to fix the Yennefer/Ciri relationship in S3.
But it suffers from the same problem with the other seasons where the writers are too busy trying to be clever to just tell the story. Like they show a party where a bunch of random shit happens then they later show a bunch of flashbacks to explain what the hell happened. You can imagine them all congratulating themselves in the writer's room on how brilliant they are to come with telling it that way.
They introduced a new character who's either a bad actress or poorly directed. Or both. There's one scene where she's holding a dead pheasant and I'm not sure if she was posing or waiting for the director to say "cut". Either way it's awkward and cringey as hell.
I think I see the direction they wanted to go. Show that she's still obsessed and starting to fray at the edges, but then give her a redemption when she realizes she doesn't need a biological child when she has Ciri right there as a daughter. It's just that every show like this seeks to have to be CW'ed these days. It's a big reason why I had to drop Supernatural too. It worked really well for 5 seasons. But after that, the 3rd time the brothers fought about X and the 6th time they kept Y secret, I realized there was never going to be any development past this and had to step away. It's exhausting.
I dont mind changing the original story if done well. Some things only work in one medium or sometimes the adaptatipn just does things better.
Good example is the boys. The comic is an absolute cringe fest while the shows is really good.