In this case, he meant the things that don't work on literally anything but the thing they were designed for (i.e. GNOME, hence not working on other common DEs like Plasma). You don't have to be that disingenuous now.
There's nothing disingenuous about it whatsoever. When two platforms aren't compatible, it's because of feature/API/dependency differences. That is
the fucking problem. So saying, "everything works equally well on both platforms, except programs that have feature/API/dependency differences, lol," is disingenuous as fuck. It's like saying, "Find me one place in this city that is unsafe at night, places where niggers and bums are don't count."
This isn't even a problem unique to the wild west of Linux desktop. Look at web development. Safari has a 20% market share, meaning a huge number of users, yet plenty of web devs don't even bother to validate their code on it. Just not worth it. Oh, you found a bug? Switch to Chrome, they tell you. Linux desktop is especially annoying, because you're 1% of the market, and that 1% is so fragmented that our support & verification costs are, no exaggeration, about 5x higher than they are on Windows, and it's only that low by dropping Debian & Arch support. It's only worth it because of Linux's huge share of the server market.
I've been developing, supporting, and selling Linux software for my entire career. When I say that the wild west nature of the platform is a problem, I know what I'm talking about. This KDE/Gnome/Wayland/X/etc slapfight is one of the major reasons software support sucks on Linux. Linux world had no problem standardizing on bash, GLIBC, and other GNU tools, all the copes and excuses for why it can't get its shit together for the GUI are just that, copes and excuses.
Yeah distros are so centrally managed that anyone can contribute to them.
Major distros only work like this in Richard Stallman's toejam-fueled dreams. You think the C++ standard is some kind of decentralized effort with no definable group at the helm? How about OpenGL? How about python? How about bash? You depend on centrally managed, uniform standards for your OS to even be remotely viable. So fuck off with this "standards go against the spirit of FOSS" bullshit. It's just cope you came up with for why the GUI is a shitshow.
The professionals have been working with Adobe products for over 2 decades now so naturally they'll choose that over something that is unknown to them.
GIMP has been around for 25 years, everybody knows what it is.