Although aspects of this method are great, I would certainly use a sling sometimes with my next baby, however it is very difficult to apply in modern society, especially if you do not have family near and just consist of a nuclear one. Also, I find it hard to stomach the idea of having sex with my baby strapped on me, i would have to put my baby down somewhere safe for that.

Also, what happens in a car, safety is paramount, you can't have a baby strapped onto you in a car, its not safe! In the Amazon, they do not have cars!

They're only strapped to you during daily activities and it's not a hard and fast rule. Of course safety is paramount so car seats and the like are always employed by parents who are following this particular way of bringing up their baby.