Should offensive/vulgar usernames be banned?

1. Does discord ban inappropriate usernames?
2. Can you get banned for having an offensive name on steam?

Does discord ban inappropriate usernames?

Inappropriate name punishments cannot be appealed as they aren't incorrect, the only way to revert this is for you to change your name to something appropriate. The ban isn't really a "ban" per se, it's a block to prevent you from using the username, after you change it, the ban will be removed.

Can you get banned for having an offensive name on steam?

Yep. At some point you'll get a ban of some sort.