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.