I don't think that's really the issue with Android/IOS operating systems. The issue is not that they can't be general purpose operating systems, it's that they

I don't think that's really the issue with Android/IOS operating systems. The issue is not that they can't be general purpose operating systems, it's that they aren't used that way. People seem to want applications that do one or two things at most and cost 1$ that they have to re-buy every 2 months. That does not result in people writing software that is very useful for a large part of a particular field, but takes 2-3 years to write. But the fault is in the app store and the lemon market it creates, not in the operating system.