Because Real Scan is only used to make a 3 dimensional model of the charecters. It's then used as a sculpting aid, similar to when a sculpter uses photographs. But instead of having to work with a flat surface which is harder to sculpt in 3 dimensions, they have a 3-Dimensional model. Shrinking a 6'+ charecter down to 4" tall would loose alot of the detail in that RealScan picks up, so that's why it can't be used to make the figures. And, IMHO the sculptors have been doing a pretty darn good job as of late, capturing the look of the charecters.
MTFBWY and HH!!
Jar Jar Binks
I dont want to sell you death sticks, i want to go home and rethink my life.