Is MF's ultimate imbalanced/OP?

Had an MF (fed, yes) who would do 2.5k dmg with ult to me despite having 180 armor. I don't like to cry imbalanced often, but these numbers just seem too out of whack taking into account MF's design and ADC balance as a whole.

Yes, you can get out of the cone. But the same applies to say ults like Fiddles (or any AoE ult), which I'd say if MF's ult is almost gonna do more dmg than Fiddles. But Fiddle's puts him greatly in harm's way. So I'd say MF's ult is as massive as Fiddle's, but late game he is completely defined by it, and MF is fine w/o her ult.

At least now I k now armor is meaningless against the ult late game, if there's a fed MF I guess I build Zhonya's hourglass if it fits my champ?