Not really. Photoshop is an expensive closed source application designed for professional use. GIMP is open source and the cross-over between professional users and open source GIMP coders is likely next to nil. Meaning that any significant production performance issues are pretty invisible to GIMP.
In my experience with the art/design mac/photoshop crowd, something like GIMP only earns blank stares.
That's backwards reasoning. Literally you're reasoning, this is bad so it's no surprise that it's bad. The reality is that it's quite surprising that the solution is simple but nobody has added it to GIMP.
Not at all - the reasoning is that the overlap between programmers and users is tiny, the programmers won't use it in the way artists do, and so problems don't get noticed. This is just what happens when you don't eat your own dogfood.
As tools go, Photoshop is pretty embedded, and most professional artists use it. Few professional artists use GIMP. (I've worked with lots of artists - this is just how things are. Most haven't even heard of it, and don't have any interest in it, which is fair enough, because most of the time it can't even load Photoshop files properly.)
Out of the artists that do use GIMP, professional or not, even fewer work on GIMP, as in, write the code that makes it do stuff. (Few artists have much inclination and/or talent when it comes to programming.)
This means that the intersection of people that write stuff for GIMP and people that use it is small; the intersection between GIMP programmers and GIMP professional users is tiny. So if there's something wrong with GIMP's implementation of stuff that professional artists use all the time, there's a good chance it won't even get noticed, let alone fixed.
I'm guessing a bit here about all of this stuff, I do admit. (How much insight do I have into the GIMP development process? None, of course.) But I've got good evidence for the theory, since most of the time GIMP can't even load Photoshop files properly! Even though that's, like, requirement #1 for anything that purports to be a useful tool for artists. GIMP is about as much use as a spreadsheet that can't open xslx files and has no OLE automation support.
In my experience with the art/design mac/photoshop crowd, something like GIMP only earns blank stares.