SF Gate: The weird reasons behind why there are so many split bathrooms in San Francisco homes
Turns out there are practical reasons why these things exist.
Because there is no sink, split baths still creep me out. The only real way to correct the condition is to renovate (which could be as easy as turning the toilet in the direction of the main bathroom after you remove that small bit of wall separating the rooms or by installing a small sink.
Other solutions fall short.
Once we saw a toilet with a sink above the tank where the tank’s lid was the sink basin. It had a faucet/tap so when the tank filled up the fresh water coming out would be there for you to wash your hands with the water draining into the tank (or so it seemed). Somehow that still creeped us out.
And while we have hand sanitizer these days that too seems to be a second-best solution especially when there are times where there was a shortage.