I at least partly blame Apple and the MAS being such piece of shit for accelerating some of the sub trends we're seeing on the Mac now. It's really such a genuine shame, because in principle the MAS really could be an excellent idea, a way to unify and simplify a pain point of Mac use and boost security at a few levels without a need to alienate anyone or not support anything. Instead Apple had to make it an artificially pointlessly limited collection of tradeoffs and mediocrity.

In particular AgileBits is right about the missing upgrade pricing system really being a bummer. To this day Apple's decision to remove that remains one of the most perplexing decisions of anything they did with the MAS (or iOS App Store for that matter). The basic idea of paying just for marginal value added since original purchase whereas new purchasers are paying for the whole package from zero is an efficient, sensible and sustainable one that has supported the software industry well since the very beginning. Ongoing support of software costs money, particularly when Apple has made it another principle of theirs to be aggressive about pushing the platform forward vs backwards compatibility. No upgrades (or volume discounts or anything else) is still such a mind blowingly stupid decision in every respect. It's forced developers to make some tough choices unnecessarily, and IAP and subs are one way to go at it.