I refuse to pay a subscription for software. If you want recurring money from me, sell new versions that have things I want.
Do you want your old software to keep working with new OS upgrades? In the case of iOS:
- If you bought an app that was created before the iPhone 4, do you want higher resolution images?
- If you bought an app that was created before the iPhone 5 do you want the app to take advantage of the full display?
--If you bought an app before the 5s that was 32 bit, do you want the app to keep working with iOS 11?
--If you bought an iPad app do you want it to take advantage of larger iPad sizes? The new multitasking features? The new drag and drop features?
Either you pay a subscription or you pay for new versions.