Well, to be honest 20 dollars per month for Photoshop is reasonable. Of course the concept of renting is not ideal, but it still gives some benefits to both Abode and their customers.
I mean, I live in Russia and even in IT many people get paid around 1000$ per month. Cut cost of living and there will be almost no money left, so if a person will want to buy Photoshop license, they will have to save money for a few monthes. On other hand, paying 20 dollars is affordable.
Though it is retarded to offer subscription as only option.