I understand you don't like William because of several things he did, but other characters like Isak (in season 1), Emma (outing isak) or Sonja (even if she apologised) did also very despicable things, and still you like them. So what's the difference?
The biggest reason is that everyone acknowledges that these characters did mistakes. The fans own up to it and the characters owned up to it (Emma should have apologised tho).
People dont romantise what these characters did like people do William. the characters themselves know they did wrong and most of them both apologised and developed from it. William didn’t change. Many of his stans don’t realise how he’s problematic at all. And also I can 100% understand why these characters did what they did, BUT i can still say that it wasn’t okay. I can understand why Isak screwed over Eva. I can understand why Emma didn’t see how outing Isak was terribly wrong. And I can DEFINITELY see why Sonja acted like she did because I know what it’s like being a human with emotions and feelings. I don’t condone their actions and I definitely don’t approve of them, but I understand them. Williams actions however? To me there were no reason for him to act like that, nothing to excuse it at all. He didn’t show any regret or development.