Little Kid Seats for Airlines

No matter you mass, no matter your girth, no matter how wide or skinny you are all air line seats (coach that is) are the same size.  I've touched briefly on this matter in my post in my "Pay by the Pound Airline".  I think every plane should have a row or two close to the front of coach that has kid size seats for children under the age of 10.  Then you could fit 4 or 5 seats on each side of the aisle rather than 3.