it's not THAT much of a wtf....
what you are physicly tomorrow will start from when you are baby till 7 years old because your bodys basics will be developed. That's why gymnastics for example have those severe looking stretching routines at the age of 3-5 because they have to do it, it's a must if they want to succeed in it.
I think these yoga whores want their children to adabt humans physical cabilities naturally, in a way that their body just will develop a ability by itself at the end with little work to follow.