While I’m sure there are exceptions, I think it’s accurate to say that Linux users would prefer function over form. I’m not sure you can make a generalization about what Linux users will buy: some use Linux because they cannot afford anything else; some use it because they believe that non-free software is immoral. On the whole I would say that the macOS and iPhone users place a premium on the aesthetics of an application more than Windows, Linux, and the dozen or so FreeBSD users combined.
Right, that's what struck me about this question too. It is not about "beautiful design" when it comes to linux software, it is about being functional and that includes being on top of all of the fragmentation when it comes to linux desktops, window managers, distributions, and libraries.
It is hard to justify paying for something when you have to spend an appreciable amount of time getting it to work in your set up. Working well out of the box and consistently with updates is the first step.
