i did not mention MenuetOS, so I will not comment about it.

Read https://web.mit.edu/~simsong/www/ugh.pdf; basically Unix is a “virus”. It was cheaper and could run on everyone’s computers and their toasters, so it became popular. GNU/Linux’s cheaper yet (free), so it became popular; that was one of the main reason GNU “accepted” Linux (also because Hurd development was stagnant).