Im super confused how you think this is new behavior for sports and also how you think this is isolated to American fans. I can link you several articles of fans in Europe throwing bananas at soccer players.
Europe is irrelevant to this. Fan behavior in the NBA is escalating and becoming bold enough that people on a nightly basis across the playoffs are blatantly doing shit and getting caught. Remember previous years where fans were banned from their home arenas every night? Me neither.
My point is that this behavior has been going on for a long time in other places. So to your point, why is it suddenly happening here? But then again, I linked the Malice at the Palace earlier. It's not a new thing.
