Why don't Tanks have attacks that can cleave multiple enemies?

[Shurrikhan]

Well I know most of you hate CC, but that is probably why.

You can't have random single target abilities in the rotation that do AoE damage. It's a nightmare to keep creatures asleep when you have AoE in ST spells.

It's neither impossible nor unprecedented in other MMOs to conditionally nullify or ignore AoE components only against CCed targets.