> So why is it OK for a software developer to just arbitrarily decide to flip a switch and remove my ability to use a product I paid for?

I see this argument repeated, and it's made exactly like this where it sets up a strawman and then brings up software.

No one is coming into your computer to repossess your software.

They are either turning off their servers, OR they are ending a subscription.

If you have a bus pass, you can do anything you want with the card. Your chisels being 50 years old, has nothing to do with you being able to ride the bus forever just because you bought a one-month pass.