Fuck that, Sapkowski hates the games and doesn't give a shit about the franchise, he only wants the money. And it's not some ''sharing success'' feel good stuff, the dude wants literally millions of dollars
It seems like his ignorance of video games was exploited. I would be resentful of the games too in his situation - this isn't 'Tom Clancy's...' situation, and I seem to recall him voicing frustrating at, at times, not being seen as the primary creator of The Witcher due to the popularity of the games.
Given how Mike Pondsmith was brought to my attention by Cyberpunk 2077 media, but I thought The Witcher was an original game series for the longest time, I can understand the problem he has with it.
As far as I see it CD Projekt used Sapkowski as a rung on a ladder to success, and by any reasonable standard haven't appropriately credited or compensated him. They might legally be in the clear but it still seems scummy to me.