2. They offered free upgrades to Windows 10 for a long time (a year?)
3. Replacement cycles for consumer desktops/laptops are short relative to OS cycles, with some internet stats saying ~5 years on average.
4. You can still run Windows 7, you just won't get security updates. You're free to repair it on your own... If you can.
5. Just because you buy an OS doesn't mean you buy lifetime support and updates.