According to this chart, which includes *A and other partners including Virgin, Business Class is 80k, and First Class is 125k.

Since Virgin seems to consider Upper Class to be business class, the OP has a point. This also appears to be the consensus of FTers in threads comparing BA to Virgin -- the comparisons tend to be Club World versus Upper Class, not FIRST versus Upper Class.

If US wants to charge F and J mileage for Upper Class and Premium Economy, they need to add a footnote to that effect in their partner award chart.