Users for whom Linux and Windows are really interchangeable are a minority of Linux users, which he glosses over as "network effects" because he's an economist. Writing software on Windows is an excruciating process you only do if you're deploying desktop applications to Windows users. Webapps became a thing first because you aren't afflicted with your users' software choices, and as much as front end web development sucks, at least you can do it in a comfortable environment. Likewise, with, as far as I know, only one exception, Linux doesn't have any kind of presence in your industry, despite the real-time scheduling work that was done in the 2.6 series to support the high end audio users who don't exist. As you've said, you use a Mac or you use Windows, because that's where your applications live. If the availability of pirate Windows is affecting your choice of platform, you're one of the users who uses a web browser and maybe an office suite and that's pretty much it, and while that's a very large portion of Windows users, it's a vanishingly small portion of Linux users.