But exactly that was not the point (to be minimally intrusive). The point was to introduce tagging that would require actively adapting your rendering/routing/whatever if you wanted to consume the tag and not to introduce even more troll tagging.
At the time my only concern was that “scramble” might be too specific a term for everything more difficult/exposed than a hiking path that doesn’t require use of hands etc. and we would end up with people arguing (because it is OSM) that something is not a scramble and falling back to path, but even that would be better than the current situation.
The one thing that is very clear, is that “incremental refinement of highway=path” will not do anything to resolve the well known issues.