Take a look at their five other industry-leading products. UX design was never their forté, but they have the rest of the design world in the bag.

As a former designer, I can tell you from experience that the designers I encountered would much rather have the newest tools at their hand for a subscription fee than be behind in software. There's so much the competitors cannot do (or can't do well), and if your prodcut doesn't work on a subscription model you're never going to be giving the latest features away in updates.