Originally Posted by Elkhound

Surely you can understand how it would be better to be able to talk to and interact with and (if necessary) discipline your children if they are in front of you rather than behind you? (The same goes for an adult passenger, minus the 'discipline' part.)
Surely you can understand that if your "live cargo" is a preverbal child or a pet, it is better to have the child/pet where you can see him/her if some problem arises.
Surely you can understand that from the passenger's point of view, sitting in the 'bak' would be more comfortable than bouncing and swinging on a cart behind.

(...)

This is not to say that carts are not useful and do not have a place in the scheme of things.