Your observations are correct and that "company" has been hauled into
court on various occasions for just such manipulations. In the early
days when this "company" was first getting started- every programmer
worth his salt was placed under contract and forbidden to write
programs for anyone else ever after. Having lost their software
support due to the above there were several computer mfg's who simply
disappeared into the sunset.
Companies who now sell computers were being PAID by this company to
only install their OS on the machines they sold. Enough of a
ruckous was made that "Some" of them now give the customer a choice
of either "their" OS or No OS. Im not aware of any that
distribute Linux yet, but there probably is somewhere.
The world is changing, there seems to be a bit of an exodus over to
linux- ubuntu and as the numbers grow Im sure so will the
availability of the drivers and/or anything else we need.