I've encountered these in several countries and are usually in more public type of restrooms. So my guess is that they are "easier" to clean. Like maybe the whole place is just hosed down or something. And if you are a woman, you just have to hope your quads can handle it! It's not easy, that's for sure.

At least for the squat toilets (hole in the ground, or something similar), you don't have to carry all your weight in your thighs!