Have you ever used one ? I actually think they are awesome. My dream in life is a washiki with a bidet function.
I'm not convinced though maybe I was just never properly trained. When I use a squat toilet I have my pants bunched up, when I squat the bunched up pants are between my upper and lower legs and cut off the ciruculation in my legs. If I'm constipated it my legs are screaming much sooner than on a seat.