Reaper ULT

Bruh why can't I cancel? Sure bad play on me for attempting to murder any of these characters with high mobility, but if the whole new overwatch cast can just leave when someone like reaper is going to kill them, why can't I cancel?

Does he HAVE to spin? If I don't collect a soul orb or obtain enough life steal during my ult someone like Kiriko headshots me easy...

I should be able to die die- wraith at the LEAST. I get shadow step kinda hard to do while spinning but if I could wraith during ultimate to leave I think that'd alone would put reaper at the top of his game.