Because Google is taking away their ability to play the game they paid for. Stadia sells copies of games ($60 a pop), and offers subscriptions for additional mo

Because Google is taking away their ability to play the game they paid for. Stadia sells copies of games ($60 a pop), and offers subscriptions for additional money for higher video quality and access to a smaller library of games. The people who purchased titles from Google are having those titles taken away from them.