I suppose you want your money back? I think it's quite excellent, and didn't find it terribly hard to learn. Yes, it's different from Photoshop, and in several ways inferior, but it does probably 70% of the stuff I need to do, for free. I have photoshop free edition anyway, if I can be bothered booting into windows for it (mostly, I can't).
If photoshop is all you know, and you don't want to learn anything different, then stick with it.
I've been using Photoshop over 20-years, since version 2.0 (~1990), and I know it like the back of my hand.
GIMP is very, very similar, and if you really know photoshop, you won't find it hard to pick up at all. It has it's limitations; it is what it is.
So too Photoshop (which IMO is far from perfect, least of all in its 'one size fits all' pricing model, and onerous drm).
I've stuck with version 6 for my own stuff, since I find later versions generally qualify as ill-conceived bloatware (I use CS3 at work).