Yeah... you have a valid point - when I go to the grocery and buy a banana - all of the future bananas I take from there are for free! Seems legit to me! Anyway as @andrewilley mentioned - you are not required. I'm just feeling bad it's a free update. It's not like the app costs 100$ - I would gladly buy it again. I've been using it for a few years now and it has always been working very well. +1 for this.
@andrewilley, will there be a way to re-purchase the new version? Somewhere back in the comments I read that the new version will be free upgrade. As a developer myself I know how much time and effort it costs to upgrade everything and do a full refactoring. I would like to show my appreciation and purchase the app again. Would that be possible?