> any sane user and I want programs to have sane GUI which does not need additional setup

In reality there is no such thing as a "sane user" using programs with "sane GUIs". Either someone already has a lot of preferences formed by their experiences using desktop OSes over the years, or they have started using desktop OSes recently and they barely have any expectations.

And because of that there is no such things as "sane user" using "sane GUIs". Your sanity is someone else's insanity.