Its because the “slav squat” – when your heels are touching the ground is more healthy and stable way of squatting .. also when taking a dump its better to squat than sit. Try it out.
I didnt knew about “slav squat” before i stumbled upon life of Boris on youtube. Squatting like a real Slav was just a natural thing to do for me .. and we arent the only ones who do that. Alot of Asian people squat with their heels down.