Because, TBH, toilet paper is a seriously flawed method:

• It takes a LOT of wiping to get yourself satisfactorily poo-free.

• And too much wiping can HURT and leave your bum raw.

• If you had a fiery or painful poo, scraping paper on it right after is basically the most horrifying experience imaginable.

• There's a risk that you're actually spreading feces around instead of getting rid of it.

• And the even grosser risk of tearing through and getting shit on your fingers.

• Turds + TP = a guaranteed clog or two.