"if GIMP hadn't been so resistant to input from artists and designers, Krita wouldn't need to exist at all"
Thats not far off at all actually.
...and I guess I should add, I still use Krita as a result of the continued overall baffle-crash of GIMPs UI and general behavior, regardless of the fact that GIMP does have a great feature-set in the abstract.
I love Krita; it's my graphics suite of choice for many tasks. But I can't help but think that if GIMP hadn't been so resistant to input from artists and designers, Krita wouldn't need to exist at all. It is a tool born of the lucky fact that someone wasn't satisfied with GIMP and had the technical skills to do something about it.
With respect to your comment about innovation, I'd be more inclined to agree if, y'know, GIMP had actually done any of that. GIMP is not innovative, nor competitive, and is unable to facilitate even fairly basic tasks for contemporary artists and designers like working with CMYK images. The existence of "good-enough" GIMP is a hindrance to innovation in this space.