I get the attraction of a subscription model from the company's perspective. It gives predictability to cash flows and makes the company that much more marketable for outside investment or buyout. I don't begrudge Camerabits for the decision. But, as someone who first started using PM 20 years ago as a student, and have been a loyal paying customer for more than 15 years, there are two things that make this rub me the wrong way.
1. The decision to make the Mac Universal release the transition point. If this was done at the release of PM7 where a whole bunch of new features were added, it would make sense. All this release does is optimize the program for Apple processors. By choosing to transition now, you're essentially charging users more for a program that simply does what's advertised.
2. The lack of an upgrade option (as was previously available) for legacy users. I think it would be totally reasonable for CameraBits to say. "For $99 legacy users can upgrade to the new perpetual license, with 1 year of updates included." I'd jump on that in a heartbeat, and I doubt I'd be alone. That would acknowledge the decades of support the userbase has happily given the company for producing a great product, while also transitioning to the new business model. After the year is up, we can choose whether to move to the subscription, buy another perpetual license, or stop paying.
Speaking for myself, I'm definitely not moving to the new subscription model, and paying full freight for a new perpetual license, when I already bought one, is a non-starter.