They need to provide tooling to enable moderation, not necessarily enforce it. Forsen's chat isn't going to change, you will still get your gachi on, but official tourneys need a way to stop the insane racism. Look at TerrenceM's comments about how he hoped his parents didn't see the chat while they were rooting for their son in his first competition - it shouldn't be that way, and Twitch (and Blizz/Playheartstone) is failing streamers and competitors by not providing anything in this area.