My guess is that no one is supposed to live there. It is one of the holiday homes of a very wealthy person, who clearly gets turned on by the idea of exhibitionism, although given it looks like there isn't another human within miles, they get to scratch that itch at minimal actual risk to their privacy.
Bath tubs are increasingly rare in europe ime. I have a bath maybe 2 or 3 times a year. Showers are for washing, baths for relaxing. So the pool can fill the place of a bath.