They're pretty successful with their belief so far and it's time to get more revenue from something new.
I've no issue with that - as your knowledge changes your opinions should be open to change. You could knock them for having strident opinions they later modify but I'd rather be grateful that they are willing to share and learn publicly as that way everyone has the chance to learn with them.
There are three major versions of Rails that are still maintained: 2.3.n, 3.0.y, and 3.1.x
> The tech and the design is all new, all fresh.
https://twitter.com/#!/dhh/status/144061889201188865
I agree that UI is really going to be the story. Customers don't need to care about what's underneath.