I should have been clearer. Their definition of "sophistication" is arbitrary and effectively amounts to "obvious in retrospect". Safety pins and catseyes aren't more "sophisticated". The inventor of the safety pin made a working version in a few minutes. Differentiating an intentional slide gesture is actually much more sophisticated than bending a wire or mounting a reflector on a piece of rubber.
It says that it wasn't sophisticated enough. Safety pins and cats eyes both require sophistication in their construction.