They're like Hondas, many backwards compatible parts which in themselves are better than the OS which runs them. You can also customize, repair and fix them easily. (re. diesel owners
)
Edit: The other bonus is that the manufacturers can put the latest components on the market faster than the big OEM's can ramp up their production with the custom cases and platforms. Plus there is a cost savings if you know what you're doing.
There are many UNIX/Linux variants run on them who can complain about that?