Yeah I highly doubt Cavill walked away because they knew a few things wouldn't work in modern day. If he walked. I don't think any Witcher fan would be upset about it either, or at least most. We all know the author was a bit of a neck beard.

However, Cavill would leave if they took a hatchet to the original material and disrespected the characters, which knowing Netflix they absolutely would.

Netflix wanted a gritty show like game of thrones but also wanted everything to be a feel good warm and cuddly inclusive welcoming show. They wanted their cake and to eat it too. It's like people forget that when GoT was at it's best it was horrifying. Your favorite characters could die randomly, there was mass death, dismemberment, rape, the very worst of humanity. The Witcher also has the absolute worst of humanity. That's the point. My best guess is they wanted to tone it down, which was not the point of the Witcher series.

The actual point of the series of anyone hasn't gotten it.

The entire time we're following a supposed emotionalless monster hunter around who everyone despises for being weird, while all the whole humanity are the real monstrous ones. That's the point, and they seem to be afraid of making that point.