Gestures are often not obvious and hard to discover; the user interface doesn’t tell you what you can do with an object. Instead, you have to remember which gestures you can use, the same way you had to remember the commands you could use in a command line interface.
The gesture is the verb. This works if the gesture is intuitive, but breaks down if there is no «natural» gesture for a verb. And since there is no intuitive, natural way of moving an object by one pixel (or skewing it, or mirroring it), we have to learn that command, and memorize it. The user interface doesn’t tell you how to nudge an object by a pixel; in fact, merely from looking at the application, you wouldn’t figure out that this feature even exists.
When natural user interfaces resort to non-obvious gestures, they essentially regress into a really pretty, modern version of the quaint old command line interface.