[dagw]

Krita was initially release as a painting program rather than a photo editing program and that was where most of the initial 'advertising' was focused. Also looking at their home page the first thing you see is a screen shot of a digital painting and the words

"Krita is the full-featured digital art studio.

It is perfect for sketching and painting, and presents an end–to–end solution for creating digital painting files from scratch by masters."

So it is not at all clear to most people that it is a tool that can also be used for photo editing.