The "subscription" system in the CAD industry isn't.
In a real subscription system, you pay upfront for a year or three, and then regularly receive something for your money every few weeks or months. (The vendor has to sit on your money, because it cannot recognize it as income until it has delivered the goods. In the case of a monthly magazine subscription, the publisher gets to recognize 1/12th of your fee each month.)
The CAD world has perverted the word 'subscription' to mean reverse upgrade. You pay upfront, and then within a year receive something -- you don't know what ahead of time. In the meantime, the company gets to generate additional income from investing the money you've paid upfront. Think how much income a CAD vendor makes from investing several hundred million of deferred subscription income.
I like the upgrade system much better: I get to sit on my money, invest it, and then pay for the upgrade only (1) if I think it is worth it after learning about the new, changed, and dropped features, and (2) when I decide to purchase it.
Now Apple comes up with a third definition of subscription: pay upfront, get the product upfront, and get free upgrades for a couple of years. In the background, Apple is recognizes the income on a subscription basis.
The customer sees nothing different from today's practice of buying a piece of hardware and then downloading some driver or firmware updates for free. For Apple, the new system is a means of smoothing income over future quarters -- allowing it to make a quarter look better by (1) shipping a firmware update for iPhone and AppleTV and (2) boosting the quarter's numbers by recognizing a portion of the delayed income.