Earlier quoted context omitted.
But this only works if you're releasing a new version every subscription period -- and in that case, it's equivalent to upgrade pricing.
If the developer isn't providing upgrades then they shouldn't keep getting paid for a product someone already bought. If the argument is that developers need _regular_ pay days then we have dedicated financial instruments for smoothing an irregular cash flow. In any case, subscriptions aren't directly equivalent to upgrade pricing even when an upgrade is provided every subscription period because in an upgrade pricin…
I think that ignores how little most developers make in the app store. They aren't rolling in money, most are just trying to figure out a way to eke out a living.