From someone that worked for a major PC OEM for over 20 years, and used PCs since the first x86 I owned back in 1986, but have owned Mac's since 2011, I have to say you've spouted some seriously misleading things here. (Kind of surprising since mostly your posts are specific and helpful. I can assure you that Windows 10 updates occur more frequently than Mac OSX updates, and in my own experience, are far more disruptive.)
To the OP, I will simply suggest that you ignore that kind of FUD, and acquire the kind of computer you are most familiar with and can afford, once you have settled on the key components that you'll need to connect, i.e., that audio interface and MIDI capable keyboard. It may be that you already own a computer that is adequate to get started, and that's probably the best option, so you don't sink a bunch of money in something that turns out to not be quite right! Starting with a familiar platform, and then learning what perhaps doesn't work well can really help insure your choices for the next computer are best suited to your own needs and workflow.
Good luck.