This is like saying to a cop that's pulled you over for speeding "I pay for your salary".
Yes, you do. But so do a bunch of other people do as well. And someone has to decide how to balance the needs of the many, which is where management / governance comes it: and said management has decided that the resources will be spent, or not spent, on certain things.
> It's more like I report a crime and the cops don't do anything about it, a situation in which I feel fairly justified being upset?
Sure. With cops, a public service. But Apple is not a public service (this is an analogy after all).
You gave them money for what they offered at a particular point in time because you thought it provided you value; has Apple taken away anything that you purchased? Did they go from x.2 to x.3 and break/remove something? That's certainly a dick move. But you are still getting what you paid for.
Apple is free to change its offerings in the future based on what it thinks its customers need/want, and you are free to re-evaluate whether those changes still provide you with value, and whether you want to continue giving them money. "I got X in the past so I should continue getting X forever into the future" has never really been promised by any software vendor.
Yes, you've made the right call trusting Apple with this, the company with famously-good backwards-compatibility and long-lived support for third-party software /s
