What is this system is remnant of is;
A very sound personal hygiene system followed for centuries, bathing two times a day, washing ones feet before entering a house, not wearing footwear inside one's house, cremating the dead outside the boundaries of the village, designated community space outside the village for natures call, two separate ponds in every village one for bathing (with separate designated bathing steps for women and men) and the other for washing clothes and a special pond inside every village temple for ritual bathing. Population has made the existence of this system impractical but that does not mean people will just change overnight relatively speaking.
In fact, up till a few generations back, most Indians would be aghast at the unhygienic notion that one can have a toilet inside one's home!
For eg. a reverse bias is, even today a rustic villager in the remotest part of rural India would cringe when he/she hears that the people in the west just wipe but not wash after they do their job (most Indians, even the ones in the west now, secretly do cringe at this idea in fact).
Why this notional difference? It could be the relative availability of water, the extremes of weather (cannot wash in icy cold water can you?) and such differences that existed in one's past which moulds one's personal hygiene etiquette.