I would also say that innovation must remain comprehensible to collectors. For example, the Zenith Defy Inventor with the 18hz superfast jiggly silicon web which takes the place of escapement is an innovation. But, it leaves me cold as I can't easily and intuitively see what part is jiggling to do what... It lacks connection and, therefore, soul. A quartz movement might be much better at that point.
Meanwhile, the Breguet 7227 classique chronometrie has a lot of innovation with a 10hz, magnetic pivots movement, but remains very easy to immediately comprehend, so is much more satisfying a watch for me. Just my take!