Ironically, despite objections, I think recurring revenue models are better for the user in the long run: it keeps the developers solvent so you don't have any "oh shit, discontinued?" moments, it reduces the temptation for feature-bloat to drive upgrades, it allows you to more easily stomach pricing the software closer to what it is worth to you (a lot) than to its incremental production cost ($0), while still allowing you to send market feedback if the product ceases to be useful to you.