Pinch to zoom is a skeuomorphic gesture, similar to stretching a slab of silly putty to enlarge a pencil drawing. There are only a few ways of manipulating the apparent size of a physical object, such as changing your view to make the object seem larger, or stretching the object itself. Any engineer translating those to multitouch would come up with similar gestures.
Also, when you mention that UX designers need to "protect" their designs, it sounds like you are arguing from an artist's perspective that all creative work "deserves" some kind of legal protection. That is what copyrights are for. However, this problem must be approached from an engineering perspective, as it deals with machines that serve a purpose, and can only be implemented in a very limited set of ways.
Also, when you mention that UX designers need to "protect" their designs, it sounds like you are arguing from an artist's perspective that all creative work "deserves" some kind of legal protection. That is what copyrights are for. However, this problem must be approached from an engineering perspective, as it deals with machines that serve a purpose, and can only be implemented in a very limited set of ways.