This is historical essay is inspired by some of the recent changes towards all gender toilets that are happening in Silicon Valley and will most likely become legal mandates.
My reminisces are that back in the earliest days, all toilets were gender neutral. The animals just did it wherever, with the bulls and the cows generally taking no interest in regulating where the opposite sex did their thing. Then along came the birds, who preferred windshields as their target, with the males and females both competing to see who could hit the spot from the highest altitude. Other variations to the rule were out there, such as the felines, who used urinating as a means of marking territory, which they did proudly for all to see.
Humans likewise paid no attention to regulations of any sort until pope Urban Organization II decided that there must be both male and female chamber pots. What was concerning him was never stated clearly, but we may wonder how it is that a prelate who only interacted with males should take note of such things. Anyway, this practice spread from chamber pots to public latrines. Then it continued to propagate throughout the world so that geographically and culturally far away places like Japan and Indonesia have also picked up the practice. There are, however, some peculiarities in these far away implementations. For example, the original Catholic practice separated the genders to the point that nothing was visible, whereas in Japan the cleaning ladies make their rounds in the mens toilets without any change to the rhythm of activity. In Indonesia, I remember some of the country side toilets being segregated, but otherwise things were more or less visible externally.
Modern intellectualoids have seen the practice for what it clearly is: Gender based toilets are a barbaric violation of the laws of nature, inspired by religious fanatics who had nothing but evil intentions and desired to impose these on others. Were it not for the brutality of the Inquisition, gender based toilets would never have taken hold. Thus, the need to compel people to return to the proper biological practices. To this end, the all-gender toilet was invented. Now I should note that there is a distinction between the simple multi-use toilet which has a toilet and a washing area both behind a single lockable door. The all-gender latrine has a relatively private toilet, but the washing areas are shared and public. My first encounter with this was at a restaurant nearby where I went, um, once. The result was that I found myself washing my hands and straightening up my clothes next to the young waitress who was doing the same. Admittedly it gave me a rather squeamish feeling, which clearly indicates the moral deficiency of my upbringing. More recently I have learned that major companies Silicon Valley companies like Semantec have implemented this in their facilities, which greatly improves the symmetry of social bonding and eliminates the suspicion generated by gender segregation.
I won't try to draw any conclusion to this, since we are still early in the change process. San Francisco, being always the most progressive, has taken the further step of encouraging public defecation and urination everywhere, which clearly brings us back to the original biological plan for such activities. No doubt the US Supreme Court will need to rule on this, followed by the World Court and the United Nations Human Rights Council. As for me, I am looking forward to a more fragrant future.