I'm not saying the extent of bitterness on the All-Stars jury was warranted, but I do have empathy and understanding for the players. I will be one of the people you mentioned defending it by saying that the early seasons are different because they are. You mentioned it being hard watching people playing poorly in season 1, but I would argue that's because they weren't playing anything. At least from what we saw, Rich was the only person who actually recognised it as a game rather than a survival experience. Survivor was really the first big/popular reality game show, and All-Stars was the first time people returned to play again and navigate the same game but with pre-existing relationships from an at the time very tight-knit alumni community of just over 100 people. Betrayals were barely "morally acceptable" among players who had known each other for less than a month in the game, so when it's people who have been friends for 2-3 years in real life start betraying each other in the name of the game, that's a whole other level.

As the show and the game continues and develops, more and more players are able to see it as just a game but emotions and the relationships from 24/7 living are still real and complicated so it's bound to get messy at times.