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.
You are right, but it’s not just poor developed countries and not just windows either.
Back in the 1990s, copy protection in general was weak and companies wishing to expand market share did not prioritize combating piracy.
They always just focused on making the big companies pay through licensing audits and kept prices high to ensure revenue.
The whole industry just accepted that students, researchers and tinkerers would pirate their software.
Photoshop, Office, Visual Studio and even enterprise software like Oracle had this dual strategy: let piracy help spread market share among those who can’t or won’t pay, while maintaining high prices and security audits to drive revenue from companies.
Many companies still follow this strategy.