It's not limited to Smash either. They've also been cracking down on Pokemon tournaments as well and I wouldn't be surprised if they've done, or will do, something similar for Splatoon. They care a lot about their image and if anything can be construed in a negative light they'll more than likely move on it.They'd been trying to shut down tournaments for years before any pedo scandals. The best explanation anyone can come up with is they don't want smash to have a tryhard image because they think it hurts its perception as a fun party game.