You draw to full scale because you can. In the end it makes life so much easier. I worked at a place where everything was scaled the inverse of 32.
So when they asked me to move something 4 1/2", well it was really .1046...(and this was on r14
( )
As everyone stated, it is more accurate and easier. If you are out at a site and want to measure how big a building is, you measure it's width, length and height. If you want to measure how far it is from another building, you measure the distance. Cadd should be no different.
If it is a solar system, College campus or something inside of your cellphone.
Pieter