ahahahaha, of all questions... =D
Squat toilets used to be common for public restrooms in mediterranean Europe, Africa and Middle East (and Russia and Japan too, I'm told). Indeed we call them "turkish" toilet here in Italy.
They're much much rarer nowadays than in my youth anyway.
I guess it was because it's a simpler design, way easier to clean, sturdier (no way to dislodge it, have pipe junctions leak, or break the seat).
It was also probably perceived as more hygenic (as you don't have to touch any surface to use it), which I think is an illusion that breaks the very first time you try to take a dump in one...
...speaking of which - why not, since we are at that - it seems that proper squatting, which I never dared try in a public toilet, with my trousers on, is a more natural and vastly superior position than sitting. Allegedly it does wonders for keeping your pelvic muscle fit, and for preventing hemorroids. In my teenage years I got a friend whose father was such a strong believer in this that he taught him to climb on the sitting toilet and take a dump with his feet on the toilet seat. It was a rather disconcerting experience to enter the bathroom and catch him at that.
And with this, I believe that this topic has definitely overstayed its welcome =D