But why does the UI suck actually? Is it because most people are used to Photoshop, and GIMP works similar but different enough to be very confusing and annoying?
That's been at least my experience. But I haven't used Photoshop in years now and got pretty much used to GIMP by now, for the once in a while that I use it.
And now I don't really have the annoyances anymore. I actually know pretty well how to do most basic stuff, and some handy keyboard shortcuts. And now GIMP doesn't feel that clunky anymore.
People keep rolling out this defence over and over in this thread, but look at those who started on anything else. For example, I've never used Photoshop, but moved from MS paint level to Paint Shop Pro (I think 6? 7?) and had to learn that from scratch. The experience was mostly intuitive, things were more or less where you expected and did what you expected, and there was solid help available under the help menu.
I have tried to use GIMP on dozens of occasions, and it always surprises me in the worst ways, or bounces me off to search the web for a howto. Simple things like: I want to select a rectangle, move/resize the selection, then crop the image to that selection. Or I want to arrange two images side-by-side for comparison, crop to the smaller one, to export a side-by-side. Pretty much every attempt at doing something other than colour curve adjustment has resulted in a faceplant. Eventually I gave up switched to Krita.
