Yeah but put yourself into the shows of a hardware manufacturer: if you'd build a Linux driver, which version do you build against? There is no reference implementation that you might use as a "if it works here it should run on every Linux there is".
If we really want good hardware support on Linux we have to at least some reference that manufacturers can use to verify it works
If we really want good hardware support on Linux we have to at least some reference that manufacturers can use to verify it works