Well, lets not jump the gun.
I do agree that developers deserve to get paid for their work, that is a given, no one is refuting this moral point. However, its different when we are talking about updates. Developers have incentive to keep their apps updated to new iOS revisions because this brings in more customers, and their old customers get to use the apps they have already bought as a perk. But holding your old customers hostage by either 1)not allowing them to update iOS in order to use the app, or 2)pay if you want to use the app your already bought, in my opinion belong in a moral grey area.
This would never be allowed in the real app store, so why is it allowed in this situation? This is like, if I spent $30 buying the entire iWorks suite for my ipad, then I need to use my ipad on the new iOS for whatever reason (development, compatibility, stability, fixes, or plain just want the latest iOS), then should i have to fork out even $1 to get the iWorks I already bought, to work with my new iOS?
So in my opinion, like lockinfo 5, they presented new features to work with iOS 6, so maybe it would have been worth a small upgrade fee, but PAID users should have been given a compatible old version to use if they didn't want to pay for upgrades and still wanted to use their apps.
While I understand in this situation its understandable that Apple keeps breaking code and its very complicated, as a consumer, I see whats going out of my pocket, so I do not like the upgrade fee concept. Sorry devs.