The cable tie sight does indeed have a history, but it has not yet been popular. Your drawings are hopefully removing the last true obstacles to popularity, and from now on people can only blame their own inertia for not being able to aim accurately with their scopes.
I don't know how far back the use of a cable tie goes, but I saw it for the first time in the mid-nineties and fashioned one on my own scope the very same day. At those days it was very rare, but I have since seen a photo where a cable tie sight was on an old Kowa TS-1 scope being used by a very well-known Finnish naturalist/birder, taken by his brother who is one of our most esteemed old-guard birders. From the scope used, I would guess that the photo was taken in the eighties, but I have never asked the persons involved what they know about the early history of the device.
The general principle, of course, is basically the same as has been used in shotgun and rifle sights for centuries.