The books are absolutely worth it if you enjoy the games. If you have a Kindle, they're pretty cheap on Amazon.
The one thing most Witcher haters/trolls have in common: having never played a Witcher game.
I have played the first game, and part of the second.
My problem is, regardless of how well-constructed the world or the game is, in the end it's a Crapsack World. There is no making it better, there's just choosing the kind of cr*p you let slide. I don't want to play in that kind of setting, where a casual hookup is a quest reward, where ideals are worthless and "least bad" and "greater good" have pretty much the same meaning.
I want a world where I can create my own hero (or anti-hero) and be more than a predefined monster hunter/mercenary. I want to play my own character, not the adaptation of someone else's frankly pretty unlikable protagonist.