What drhotwing1 will not reveal is that for some reason, they chose not to work with the Mac App Store. There are many software titles that can process updates and add-ons via the MacAppStore, so I am not sure what the issue is... My guess is it may revolve around $$$... Maybe Apple wants too much of a cut of the revenue?
Another flaw in drhotwing1's logic is that, just because the Aerofly declared the Mac version a full product, it will be received the same way by the customers. Aerofly F'ed up by releasing on MacAppStore if they were not willing to support. They should have just offered the Mac version as part of the Steam product, but they opted for the extra $$$ of a separate sale. Now they have a customer relations issue.