Windows as a software package would have never been affordable to individuals or local-level orgs in countries like India and Bangladesh (especially in the 2000's) that are now powerhouses of IT. Same for many SE Asian, Eastern European, African and LatinoAmerican countries as well.
Had the OS been too difficult to pirate, educators and local institutions in these countries would have certainly shifted to Linux and the like. The fact that Windows could be pirated easily is the main factor that led to its ubiquity and allowed it to become a household name. Its rapid popularity in the '00s and early '10s cemented its status as the PC operating system. It is probably the same for Microsoft Office as well (it is still a part of many schools' standard curricula).
The fact that Windows still remains pirateable to this day is perhaps intentional on Microsoft's part.
Yup, when I was talking with a few different Microsoft representatives, they just straightforwardly stated that they don’t focus at all on punishing or pushing consequences for “obtained/purchased windows instances via any existing alternative/not supported ways” when it comes to private/home users.
They surely and happily will put the idea of buying a key or official upgrade from their certified resellers locally or online on the table.
It is quite a different story with larger organizations and companies.
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Of course all this info is based on just a few talks during the last decade and with incoming subscription (ugh) model a lot will change, I guess.