If an app is a front end to a service that by its nature must be a service, a subscription model makes sense. Outside of that, though, a subscription model is a showstopper for me. I may subscribe to a service if it's important enough to me, but I will never rent software.
I understand that view, but it's just not that simple. Firstly you don't "own" any of the apps you've bought: you've not bought the executable, you've bought a license to use the executable, a license which may be terminated for any number of reasons: some by the developer, some by Apple. Second, due to Apple making changes to their OS, that app you've bought will require updates and I've chosen my word very carefully there, it will require them. Those updates take work; believe me I've held a few apps in maintenance mode in my time, it is not idle work. It involves a lot of testing of new iOS builds and updating projects/implementations of Apple's code, on and on. It is not a nothing job.
So you has my theoretical customer who've bought an app for a fixed one-time purchase would presumably have something to say to me in the form of an email if Apple drops a new iOS update, and the app no longer works, right? Because you paid your money and you want to use this software. And I totally agree! I want to update it and keep it working for you. But the one-time purchase model is not conducive to this relationship, because it's effectively infinite time investment for me, and a one-time payment for you. And the amount of money I can make to justify that time investment has a natural ceiling: people only need to buy my app once to use it on all their devices, and no matter how good it is, there's a natural ceiling in terms of sales I can achieve, because only so many people are going to want it.
Again, I don't really have a solution to this. The economics of app development are tricky.
It is for me, and when it comes to what I'm going to spend my money on, that's all that matters.
> you don't "own" any of the apps you've bought
I'm sure that you know what I mean here. I "own" it meaning that I am in possession of an installable that isn't dependent on an outside service, and that can't be modified or removed without my permission.
> due to Apple making changes to their OS, that app you've bought will require updates
I don't use Apple devices, and if Apple platforms are that unstable, then that's a good reason not to!
> I want to update it and keep it working for you
So you charge for the update. You don't charge an ongoing monthly fee.
This stuff isn't actually that complicated. The industry worked it out pretty well a long time ago -- it's just that all of that knowledge has been disregarded in favor of a subscription model that allows a deeper soaking of customers.
