Despite Tokyo’s tremendous number of convenience stores that by and large now tend to have a toilet, many Japanese men of a certain age still have a puzzling predilection for peeing in public, with their desperate discharges often done with a total disregard to people passing by.
A propensity that quite possibly prompted the owner of this ideal-for-a-quick-wee wall to try and persuade them to at least piddle on somebody else’s property.

Although there again, as it somewhat surprisingly suggests that only spending a penny when standing is deemed undesirable, females and even fellas with a penchant for the previously posted Angel Lap Pillow are presumably still ok to pee.

Perhaps.
Had to read the kanjis to understand your connection. 立小便禁煙 (stand, pee, not allowed). 座小便禁煙 (sit, pee, not allowed) would be Ok, wouldn’t it.
It certainly seems that way Peter. They only appear to have a problem with the standing variety!
If dudes in Japan had more fart jokes then they’d pee less in public.
According to my dictionary, 立小便 refers specifically to urinating “outdoors (by the roadside, against a wall, against a tree).” Look how educational Tokyo Times is getting.