Yes they can. They can focus on a specific model, even work directly with the OEM (or be the OEM), put a $60 price tag on the box, and have a warranty that says

Yes they can. They can focus on a specific model, even work directly with the OEM (or be the OEM), put a $60 price tag on the box, and have a warranty that says "We guarantee that this Linux distro will work out of the box on model X; we'll keep all the software updated for a year; you can call us if it breaks; and we'll refund you if we can't help." If no one can make that sort of guarantee for money; why should I even bother trying to do it myself?