Wrong. Cost efficiency can be proved and shown using a mixture of stats and variables. It's a relative aspect of a unit, related to efficiency. If it can't be showed using logic and stats then it's all made up and hysterical.
Riflemen can not be cost effective but they get the job done on the shorter run, I wonder why no one mentioned that before?
I even agree partially with shadowlink about USF being bland, but having good units.
Usf is more exciting to watch than okw, Brits, and Soviets. It is the early game doctrines which makes them a pleasure to watch. Pros are using cav riflemen, assault engineers, rangers, or paratroopers instead of riflemen spam.