There is no such thing as a user interface which is naturally "intuitive". Discoverable user interfaces provide consistency and affordance. If a new operating s

There is no such thing as a user interface which is naturally "intuitive". Discoverable user interfaces provide consistency and affordance. If a new operating system or device uses similar affordances to things a user has seen before, they can rapidly transfer their experience. This is usually what people mean when they call a UI "intuitive": conventional. Users always have to learn, and as user interface designers we must give them a path for learning. If there's no path to learning about a feature, it might as well not exist, irrespective of whether you consider it "secondary". Gestures, by design, have no afforances. Pinch-zoom is nearly the only multitouch gesture that has been so universally accepted and applied that it can be taken as given. Pressure-based shortcuts, in the absence of corresponding visual cues (as implemented by Apple), likewise have no affordances. The 3d-touch hardware was great, and worked as intended. iOS used it in an opaque, undiscoverable manner, and the result was a total dud.