I'd argue it's a bit of both. In my case, I have an iPad 3, which runs iOS 9 compatible apps, but iOS itself doesn't backup the app files, so when various developers pulled their files off the app store for those old iOS versions, I lost access to the old software that did work, which really doesn't make want to buy another iOS device. Less of a problem on mac though.
I'd argue it's a bit of both. In my case, I have an iPad 3, which runs iOS 9 compatible apps, but iOS itself doesn't backup the app files, so when various developers pulled their files off the app store for those old iOS versions, I lost access to the old software that did work, which really doesn't make want to buy another iOS device. Less of a problem on mac though.
I guess if it was a paid app I can see the irritation that would cause. Free apps not so much.