> The less coupled software is to hardware, the less likely it is tested in that hardware and the higher likelihood of bugs.

Yes, exactly! There are whole teams inside Dell etc. dealing with this. The term is "system integration." If you're doing this on your own, without support or chip unfo, you are going to (potentially) have a very, very bad time.

> This is not the fault of hardware makers.

It is if they ship Linux on their hardware.

This is why you have to buy a computer that was built for Linux, that ships with Linux, and with support that you can call.