I used to think that MS were probably happy with a certain amount of “piracy” (students, voluntary groups, people starting off as self-employed contractors, etc.) because it kept people in their ecosystem (using MS Office and other Windows-only software), helped reinforce the perception of Windows as being the OS for getting stuff done (either work or games) and some of these “pirates” would become future (paying) customers.
Of course, if you were an avowed pirate, nothing even slowed you down.