Well, firstly I think we ought to at least insist that people use bicycle=discouraged/impractical/nonadvisable/whatever (instead of =no) whenever the criteria for it are based on practicality instead of explicit signage or law.
Furthermore, my point on multimodality stands. A way that is ‘impractical’ for a normal bicycle is often fine for an MTB. A way ‘impractical’ for the Stereotypical Sunday Stroll is often fine for hiking. So presumably we’d need to have ‘impracticality’ tags for all the different vehicles and modes. At that point, we’d just be duplicating descriptive tags.
Notice again that a legal restriction on bicycles almost always covers all bicycles (ditto for Sunday strollers and hikers). So the self-explanatoriness of these cases differ massively.