I find this drawing program simpler to use than GIMP, while having lots of advanced functionality and maturity.
GIMP is a general image editing software while Krita focuses quite specifically on digital painting and art, so it is not surprising that you find it more ergonomic for drawing.
I don't to digital painting and art and I still prefer Krita. Although prefer is the wrong term, I despise GIMPs botched, unituitive and cumbersome UI so much, I'd rather code a figure in html/javascript and canvas or svg, before I'd use GIMP. Krita on the other hand is relatively nice to use.
Btw there is a new fork of GIMP, called "Glimpse" [1], that tries to improve the UI. Their first release was just a re-branded GIMP, but maybe they'll get something done someday.