[wlesieutre]

Assuming that the cost to users of paid upgrades versus subscriptions are the same, which I don't think is a good assumption.

Paid upgrades I only had to buy when they were worth buying, so often I wouldn't. I was using Photoshop CS5 for quite a long time, well after CS6 came out and then into the subscription era, and I got a great value out of that purchase even as someone who wasn't using it professionally.

Subscriptions can keep on charging me the same price even when development is stopped or focused on features I don't want. Keep paying forever or you lose it.