People who hate Harry Potter missed the a giant part of the story. Despite being abused by his aunt, uncle and cousin his whole life Harry was kind, compassionate, loyal, protective and honest. He defended those who needed it and stood up to those who deserved it. He didn’t become bitter or hateful. And he spent his life trying to protect others. You can’t hate him because people chose to stand by him even if it meant they’d die. He didn’t want that, he wanted everyone to live even if it meant he couldn’t anymore.
It’s because he suffered PTSD in book 5 and was mistaken for a whinny angsty teen.