Two pivotal moments for me and I assume may others on the Warriors:
1. The PC after Game 4 last year. Two guys who grew up with every possible advantage as wealthy children of NBA players crapping on a guy like LeBron about toughness in the NBA was off-putting. Didn't help that their teammate who was already famous for nut shots had just punched LeBron in the nuts.
2. Durant, obviously. He of course has every right to play where he wants and the Warriors obviously should do everything they can to build a dominant team, but fans also have a right to reject it if it negatively affects the game, and IMO it does. The regular season was great and the playoffs are still gonna be awesome and fun, but those things are obviously way better if the champion is unknown. This championship was decided last July, and barring an injury or another crazy development next year's championship is decided too. That's not appealing to anyone and it's reasonable to dislike the people responsible, even if they're not doing it just to be #######s.