Fair enough. I'm not sure a mechanism for having paid upgrades under the same name as the original app would have avoided any of those headlines, though.
You don't? If people had complained about being charged a reasonable, discounted upgrade price for Tweetie 2, they'd have been laughed at. That has been a common model for software upgrades for as long as I remember (and quite probably longer than I have been alive).
People always complain about being asked to pay to upgrade. If they don't get a discount, they complain about that. If they do get a discount, they complain that the upgrade "should have" been a free minor version bump instead.
In my experience, at least, it's more or less just a pathological behaviour that you can't escape.