Wow, yeah, that's super unpleasant to look at. I'm really not sure why, gradients usually don't bother me. Must be some subtle detail, maybe the gradients are too long or too short?
This is really surprising to me. Wouldn't this make it a good deal more expensive to produce most kinds of apparel and some merchandise? Maybe I'm out of date on modern printing and embroidery tech.
And thus, as all other app icons follow suit, gone are the days of simple colours and long shall the days of soft colour radial gradient app icons reign supreme...
... or at least until the new icon fad comes along and all other apps jump into line.