It's bizarre that a search bar that unfolds a vertical menubar when highlighted but unfilled is supposed to be a great advance. It's so unimpressive that I 1) don't mind it at all, and 2) think the menu aspect is useless. It's just a menu command search bar; a good UI library could construct one automatically. Stick it in a corner, or automatically open it when people start typing with no obvious object. It's a triviality.
What bugs people about the GIMP is that it's not Photoshop. All of the GIMPs menu options are placed in eminently logical places. although it's a grammar that probably makes sense over time. Photoshop options are mostly placed randomly, and some of them turn out to be ads. That's not a huge dig at Photoshop, because it's pretty amazing that they ever fix or move anything with so much industry adoption, and adding things has to be a nightmare.
But the GIMP puts things in places because they make sense there. They don't have the base that would get enraged if they moved things. It's extremely telling that when put to specify improvements that could be made, the suggestions are either trivial, like
1) a search bar, or
2) an extra statusbar above the statusbar (in case they want instructions over their instructions), or
3) to make it single-window (because just not moving things is not enough, they have to be prevented from moving things),
or they're just:
4) "Make it more like Photoshop! When I use Photoshop I know where things are, and when I use GIMP, I don't!"
The GIMP is wonderful and its problems are technical: it has lacked some of the ability of Photoshop, but that gap slowly but surely continues to close.
edit: I can't believe I forgot the worst one: "Why when I click Save does it save my project, but when I want to export a file based on my project, I have to pick Export?"