Odd, as in my experience it's the opposite, and it would be considering the API's that the PC is always forced to go through. Console *ports* are generally very low CPU usage (my X2 215 Athlon is very rarely the limiting factor in getting significantly better framerates in console titles than their native counterparts), but that just seems to be due to the required level of optimization.
CPU-hogs are far more often games that are designed for the PC from the outset (Metro, Stalker, RTS's for example).
I'm not sure where you are disagreeing with me though?