>>343462because i have a small apartment, and keeping a litterbox in a small apartment stinks no matter how many times you clean it per day.
also, no matter what litterbox i get, or rug to put it on, every cat ive ever owned has found some scheeming way to get litter all over the place, which is the most awful thing to step on with your bare feet.
also also, i like to let my cats lay on my bed, lap, table, wherever and i dont want their paws tracking shitlitter germs all over the place.
also also also i want to be able to laugh at my family because they bought a dog, and they cant even train it to piss outside the house, no less in the toilet.