If you want a definitive answer, you'll need to ask him I'm afraid.
My best guess is that Windows development was the thing he was most familiar with (or even only familiar with). The coding style was also similar to one commonly used in the 90's by Windows developers.
First of all, let's make costs clear. If power is extremely cheap for you (perhaps you make your own or have surplus from self-generated solar/wind), and you properly cool your GPU so that it does not burn itself out, then you MIGHT get a tiny amount of BTC from mining with a rig.
Nice Hash gives you about $1.78 per day for renting out an Nvidia 1080 Ti, so ...