Totally and completely agree.
A philosophy says that being a BIM software, everything shall be shareable to an extend. But since forever, the copyright matters, the invested manhours among other things, had been very important issues for many companies to keep being competitive or any other reasons.
Due to the lack of these tools, we keep sharing 3D autocads or IFC models to other Revit users such as consultants or contractors just to avoid that some families start leaking. Yes, we can have all the disclosure agreements but even so, any person in any moment, can copy a family from a project and becomes public.
If not possible to password protect the model, projects or whatever...maybe an option to export the model to a special Revit Sharing Model that doesn't allow to Edit Family in any way, or, perhaps that exports the family types modeled but strip them from all parametric functionality. The data, dimensions, and information would remain, but the dynamic behavior won't.