Great interview, and I certainly agree about the user-experience aspect. While it's important to keep new features coming and developer interests satisfied, it's also important to finish, and make more user-friendly, core aspects of the product. I don't feel that's always happened with WordPress.

The example I often come back to is comments. It feels like once a 'working' system was completed, that aspect was left and development moved on to 'bigger and better' things. And while I've been glad to see improvements to the editor area more recently, it is an area that could use much more work. Those are core areas of the product from a user-experience perspective.

I'm still mixed about the customizer, too. Maybe I'm not seeing the big-picture of it yet, but it feels like a step back so far. Maybe it's nice for a brand new user, but I think most of us have just gotten used to having two browser tabs open. And, doing so, IMO, is more efficient. The customizer does give visual feedback, but for me is a more awkward method (and inefficient screen-space-wise) of working.