The highest percentage of PC-gamers can be found (at the moment) on Windows. Ergo, you will write Windows games and use libraries Indie game developers want to

The highest percentage of PC-gamers can be found (at the moment) on Windows. Ergo, you will write Windows games and use libraries Indie game developers want to reach the largest audience as well, so I don't see the difference. Additionally, the fact that Windows has such a high marketshare among consumers means that it likely has a high marketshare among indie game developers from the get go.