I find it truly bizarre that there are people who actually still buy a Mac Pro. Just look at the shop page. They sell that thing for 4k$ with 16GB RAM and a 256GB SSD. It's completely bonkers. If you need a high-powered audio machine with dedicated PCI-E ports today(!), there's simply no alternative to a Windows PC. And yes, Windows can do audio just fine; you either invest the work and carefully choose components and build it yourself, or you buy it readily from 3XS, VisionDAW, whatever.

The difference between a $1.5k Windows machine and a $4k Mac, with the intention to use either for the next 4-5 years, is nothing compared to studio budgets. Audio engineers spend tens of thousands just on room treatments, thousands more on analog mic preamps, and you need a hefty collection of different microphones. This is all so that you can bill studio time at $500+ per hour and produce great recordings. Any time you're spending diagnosing blue screens and Windows driver issues is time not booking artists and preparing mixes. OS X happens to be the first-class platform for most DAWs like Ableton, and the only choice for Logic, so you're limiting yourself not using a Mac.

There used to be some timing issues with Windows audio 10 years ago that forced people to go for alternatives but I think it got fixed in Windows 7. Now Apple's ignorance and total lack of innovation makes people move to Windows. I think it just shows that market forces work.

Yes, Windows used to be terrible when it comes to audio, but that was a long time ago. Of course, any badly written driver can still destroy everything, that is why you have to choose hardware carefully. But with a good ASIO driver you will achieve very low latencies without problems.

In commercial environments the OS starts to not matter so much. The machine is literally bought for one purpose and that alone.

I have worked in environments where vendors actually give a proper legally binding guarantee that Windows boxes work as expected and they charge accordingly.