That's part of the difference. With a subscription model, you don't need customers to want to buy your upgrades (they're forced to pay for them), you benefit the most from locking them into your ecosystem as best you can. Adobe doesn't want to make existing customers happy, they want to make it difficult for unhappy ones to stop paying every month. At that point, discounts to new customers makes sense, since it traps new people into paying you.
Trapping people into paying is never going to be a successful long-term strategy.
I tried to unsubscribe from Disney+. Their website says all over the place "cancel at any time", but I could not find any place where I could cancel it.
I wound up canceling it by getting my credit card company to block their charges.
It left a pretty sour taste, and I'd be very reluctant to ever sign up for it again.
That's part of the difference. With a subscription model, you don't need customers to want to buy your upgrades (they're forced to pay for them), you benefit the most from locking them into your ecosystem as best you can. Adobe doesn't want to make existing customers happy, they want to make it difficult for unhappy ones to stop paying every month. At that point, discounts to new customers makes sense, since it traps new people into paying you.