My strongly held suspicion is that it’s a form of the dunning-kruger effect. People have a lot of experience using software-A so much so that they tend to overlook just how much skill and knowledge they have accumulated with that specific software. Then when they try software-B they misconstrue their lack of knowledge with that specific software as complexity.
You just answered yourself. They’re just tools.
I’m a professional graphic designer and I will never EVER support any initiative trying to get privative support into Linux and this kind of shitty mindset from colleagues actually irks me. I will support any initiative trying to improve what we already have. You don’t even need to be a developer nor donate money to help - bug reports and translations are also a thing. That’s how we got to get high quality software like Krita, Inkscape or Blender.
I’d suppose if you ask this on KDE Reddit someone with enough time could make something like this with Kvantvm, though the difficult parts would be (1) the web browser theme, and specially (2) the icon theme - I have never ever seen an icon theme like that for Linux