The problem is, the devs are looking to optimize an entire game, while we're going off on one screenshot to say "that's bad!" or "do this!". Perhaps if you make it like the second screenshot, a second after the screenie an explosion takes place that is WAAAAY too bright, thus the first 'grayer' option is more desirable. Though I couldn't see your picture of the Witcher, I think you're talking about the part you spend in "The Fields", right? That was disturbing, to me. It was also the most difficult part for my pc to process. I had framerate issues, even though my PC is pretty strong. I don't know if it matters how bright the area was, but I don't think that it's altogether so simple as "I like Screenie 2 better"
The first one looks as if the sun is blocked by the clouds a bit. The second one looks as if the sun is shining from right above. They're a bit different, but I don't hold either one as "better".
