This is one of the inherent problems of being closed source, support for niche and older hardware will be lacking.
Microsoft have to break compatibility from time to time in order to progress, either due to hardware changes (64bit) or software changes (new video driver stack etc).
The problem is that with closed drivers, only the original authors of those drivers can change them and hardware manufacturers have little or no incentive to continue supporting old hardware as they want to sell you new kit. With open source drivers, all it takes is for one of the users to either update it themselves, or hire someone capable of doing so. In some cases updates aren't even necessary, eg a lot of linux drivers written for 32bit x86 compile just fine on 64bit or even other architectures like ARM.
The same is true of niche hardware, a lot of hardware was intended by the manufacturer to be connected to x86 systems but uses standard cross platform buses like pci or usb... While the number of people using linux on ppc, alpha, sparc or arm etc might be too low for the manufacturer to bother providing official support, the drivers will often just work. I used to run an alphastation on linux with all manner of pci and usb devices which were never intended to be used on alpha based hardware.