I guess I have a different interpretation of the term patina. To me, the term is more along the lines of the classic definition of it. If you set aside the primary definition regarding an applied oxidation on metals. A layer or effect to the surface from years of use and handling. Like the patina on an old tool for instance. But not a tool that has been left to neglect and atmospheric degradation, like rust. Or like loss of paint due to human sweat and/or abuse. Most of what we find on old bikes isn't patina, in my view. It's damage, from neglect. Or use. But there ought to be another name for it besides patina.
Patina is a good thing on many old collectable things, like wooden furniture, vintage tools and so forth. And should be left undisturbed. But rust and evidence of neglect are not good. And not patina, IMO.