The biggest reason that audio software/hardware manufacturers tend to ignore Windows is its latency problems. Latency is the amount of time it takes to send input to the system, or to get output from the system. Total latency is the combination of the two; how long it takes from the time I pluck a string until I hear the processed version play back through my headphones. High latency throws your timing off. It's a lot like when you speak into a microphone in an auditorium and the delay between when you speak and when you hear your voice is confusing.

The two primary audio APIs available on Windows have very high latency, to the point where they make tracking with effects virtually unusable. You can increase your sample rate to improve the latency, but that is far more taxing on your CPU.

OS X uses a system called Core Audio, and it has very respectable latency and is comparatively easy to develop for. We're at the point where a sort of self-sustaining feedback loop is well under way. Poor latency causes musicians to prefer OS X to Windows. Audio hardware manufacturers want to release products for platforms that people are actually using, so they target OS X. Now musicians who were on the fence about switching to a Mac have to in order to get access to decent recording equipment.

I have an Apogee Duet that works on OS X and iOS(!), but it doesn't support Windows. The really weird thing is that I get better latency when recording through my iPad then I do when recording through my beefy gaming rig.

tl;dr: Nifty controllers won't fix the problem. Microsoft needs to get serious about audio performance if they want musicians to use their platform.