I’m not so sure that counting on “common sense” passes the verifiability principle, though. I would prefer the extra wording (which surely need not be “guff”?) to clarify what is meant. Because it seems that to some it is “common sense” that the e.g. nondescript rocky mountain with few rocks moved together constitutes trail_visibility=excellent and to others trail_visibility=none.
Such discrepancy seems undesirable outcome to me, and is clear indication that the wiki is lacking and should be improved. Sometimes a few words can speak more than a hundred pictures…
If the intended outcome is that only those who map on the ground get voice (which BTW seems will soon be deprecated according to the OSMF Board Task B501 in favor of armchair mapping, but I digress), I’m afraid the proponent of that idea might be in for a rude surprise 