You probably need a newer version of gcc.
This helped me fix for Ubuntu: https://askubuntu.com/questions/1140183/install-gcc-9-on-ubuntu-18-04
TL&DR: adds custom PPA repo so you will able to upgrade:
sudo add-apt-repository ppa:ubuntu-toolchain-r/test
sudo apt update
sudo apt --fix-broken install
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.