I searched both the SDMB and Google and found no answer.
To quickly see if there’s anyone occupying the stall
It’s cheaper this way
Easier to clean the bathroom this way
The lock on the stall can be made to show red if it is locked
and green when it is not locked, so you can quickly see if
anyone is occupying the stall (like in airplanes)
How much money do a few inches of that cheap material cost,
compared to the cost of the bathroom as a whole?
Maybe point three is somewhat valid, but I don’t think it makes
cleaning that much easier
Anyway, does anyone have any thoughts, or does anyone know
the actual reason? (If there is an actual reason)