"How does it help you if your potential customers avoid your software like a plague?"
You're gonna have to show that would be the result. You'd also have to show that whatever your alternative idea is. You said you want to "break natural constraints on availability." How are you going to do that without charging per copy, or charing a subscription model? And how does your idea make more money that previous, or at least a similar amount?
"Subscriptions border on restricting somebody's financial freedom."
I am fine buying software but only if I can keep ownership of whatever version I bought. I shelved money for complete CS6 but stay light years away from CC. I bought Ableton Live Suite, but stay away from ProTools. Imagine I had to pay Nikon or Access a yearly fee for camera/synth in my studio?
I have a plenty of money I want to spend on software but only if it empowers me and not if it treats me as an ATM. For example, the old JetBrains model of buying a new major release (and keeping it forever) and then getting free updates for a year was simply perfect, both for allowing developers to love the company that treats them properly and financing ongoing development; not sure why they regressed.
You're gonna have to show that would be the result. You'd also have to show that whatever your alternative idea is. You said you want to "break natural constraints on availability." How are you going to do that without charging per copy, or charing a subscription model? And how does your idea make more money that previous, or at least a similar amount?
"Subscriptions border on restricting somebody's financial freedom."
No, they don't.