Maybe it was an outlier, but a friend had a visceral reaction against the design aesthetics of his demos and thought the principle examples he gave were depressing. Overall, since I've evangelized in my humble ways the message from the talk, I've learned that not everyone believes that a principle based approach is the ideal path. Some are interested in solving hard problems for the sake of solving them, and others are interested in making lots of money. Nothing inherently wrong with either, but still a bit surprising for some reason.