I’m talking out of my ass, but I believe they couldn’t really convince the non-techies to upgrade from 7 & 8 to 10 either.
The average Joe doesn’t give a shit. They simply booted their computer one day and oops, it had upgraded itself to 10.
Microsoft could have almost this entire userbase on 11 by now without them even knowing thanks to 10’s automatic updating, but nooooooo they just had to require TPM or some shit.