There are very few places where the AOE-damage from supreme cleave matters much anyway, since in 90% of content (and yes that includes epic quests) the trash is easily wailed by the caster. It's nice in some desert epics, places with lots of epic drow and elite shavarath, but otherwise all the trash will be dead anyway by the time the barb even gets there.
Also claims that barbarian dps is lightyears ahead fighter dps are just silly. Barbarian gets ahead when fighter runs out of action boosts and power surges, but that won't happen in most content anyway, only in places like ecof and edq1.