Shout out to Dublin, that closed all its Victorian public inner-city toilets b/c it couldn't be bothered to police them (much as it doesn't police ASB anywhere), shifting responsibility to local businesses, most of which are now "Toilets are for customers only" as a result..

Or even simpler - build more green spaces with grass, shrubbery and trees. Peeing on those is harmless and they provide other significant benefits as well.

I was recently in Amsterdam (you know, the place where they said "welp we'll never fully outlaw prostitution & drugs so let's allow but regulate") and appreciated a series of very public urinals. Which I assume follows the same logic "people are going to pee on the street no matter what, let's give them a place to help control it" - I quite like the idea that acknowledging certain human traits are essentially a force of nature, so why not redirect that firehose towards a more tasteful target than impossibly try to stop it.

See - https://en.wikipedia.org/wiki/Pee_curl

I rather buy the idea that the secondary explanation is actually the primary reason. In the first picture you can clearly see such a structure in a corner that doesn't connect to any kind of street/alley. Thus, I personally, don't buy the primary reason. Of course, unless that specific spot was made much later in time.