I actually think this is great. I've enjoyed using Krita (even though its sometimes a PITA to get setup) and its rapidly surpassing everything GIMP spent a dozen years trying to pull off.
Krita's just lacking a OSX build. I've been using the windows build for a while. Krita's focus is on digital painting. I would say Krita is more comparable to Corel's Painter instead of Photoshop.
Krita is actually built on Qt libraries, just like VLC and even some of Photoshop. Which makes it look native on most platforms, and AFAIK won't require X11 on OS X -- because Qt uses Cocoa there.
The other workaround I can think of is to use Krita in VMPlayer(Fusion?) with Ubuntu. Sounds clunky but I'm doing that with the devel version of MyPaint . Wacom usb pass through on Virtualbox isn't working well.
Part of the reason Krita development has accelerated massively in the last couple of years is that its team decided on a clear mission statement at some point, one very different from GIMP: Krita is a painting app first. The main use cases are painting, illustration and texture-making. That it's also quite useful for cases GIMP traditionally aims at (photo editing, web graphics) are down to toolset overlap between the use cases and a robust, modern tech foundation (colorspace-independent implementation strategies, etc.), but Krita isn't actually trying to compete with GIMP and ventures into territory GIMP doesn't really serve.
Can you compare Krita and MyPaint[1]? (In terms of features, completeness, UI, etc.) From the video, it seems that Krita is a bit more advanced, with image transformations, texture tiling and probably other features. But both programs are digital painting applications, much more than GIMP, which is a generic graphics editor.
Krita and MyPaint share a common interest in implementing things like sophisticated brush engines and color mixing models, and MyPaint is strong there and has been an influence on Krita (perhaps also vice-versa, though I don't follow MyPaint as closely).
One difference might be that Krita existed as a project to write a raster graphics editor for years before deciding to double-down on painting, and did quite a bit of broad foundational work in that space, like aiming to operate colorspace-independently and implementing various general raster editing tools (e.g. a sophisticated layer and adjustment layer system). Krita retains those traits today, which I feel makes it broader in actual scope than MyPaint, which I think directly started out as a personal project to write a stylus-driven painting app and then grew out from there.
Krita bogged down when I tried using a 12,000x12,000 canvas. It also took several minutes just to show the canvas. MyPaint handles frames several times larger with no slowdown on the same hardware. Krita has a better interface overall, but I like to work big.
I think that is only part of the answer. The Krita team is also a lot more compact and has a clearer, more internally defined end goal (it will be interesting to see what happens if its userbase explodes).
Less of the glacial Debian-style politics than have encumbered GIMP never also helped Krita.
Make it crossplatform and you have a BIG win.