

I’d agree with the: come preinstalled. Most people buy a device and never change the operating system. So it needs to be the preinstalled operating system on the average computer or laptop, wherever people buy those.
(And mind that Linux completely dominates the market on servers. So technically, a lot of people use Linux in a way… Just not on desktop computers.)
I don’t think Microsoft are that clever or malicious. There are third party drivers available and I don’t know what all the Linux parts in Windows these days are able to do… So it’s definitely possible. But I think you’re looking more for a targeted attack with this. Like an agency or a hacker singling you out because they know you have valuable data on that filesystem. But Microsoft’s business model is more fishing for the easy targets and funneling data en masse, not the niche stuff… That might change at some point one day once the Linux subsystem automounts filesystems or something like that.