Other people can send you stuff, though I haven’t tested this.
If Blizzard did this then Bots would find a way to use it to get their accounts unblocked.
It seems that Blizzard’s only reply is just to wait for 30 days, that’s a long time in gaming, usually I’ve finished most single player games in this timescale.
There does need to be a way for legitimate players to remove this but every way I think of can be used by the bots too. From fake IDs to authenticators and IP/MAC address banning, nothing won’t catch innocent players as well.