Why aren't slurs an INSTANT ban?

Listen, it's in the title. Why the hell are valve allowing people to say shit like "Jewman" and "retard", along with a multitude of others slurs I can't say.

I can accept toxicity, it comes with the genre and I would be a hypocrite if I didn't say I haven't lashed out at people online. You gotta have thick skin to be in these games, I get it.

But the amount of games I get people calling each other slurs in Oracle-Phantom lobbies is insane. I just mute them, report them, and move on, but I know for a fact these people keep playing the game because I see them in other games at a later point.

Why is this allowed? Do we really want to foster a community of people who think its okay to get called N-Lover because you asked them to not run up and die alone? This is insane. I swear it has been getting worse since the games been around.