Is there any reason why Ori's ult stops mid way through casting when you die?

Seems a little unfair when you cast your ult right before you die and it doesn't work. Animation goes off, you see it's pulling animation right before the effect follows...Then you die and it doesn't work. Is it because of some lore related thing where she dies and the ball dies or because of something else?

It reminds me when I used to play pantheon and his ultimate wouldn't show the CD so you're stuck with it displaying it as ready to use but really there is an invisible CD.