Perhaps the ides is that the sin is not in doing it, it is in getting caught doing it.
How does the joke go?
THREE RELIGIOUS TRUTHS:
a. Jews do not recognize Jesus as the Messiah.
b. Protestants do not recognize the Pope as the leader of the Christian faith.
c. Baptists do not recognize each other at Hooters or at the liquor store.
You could also see this from the angle that streetwalkers could easily be diseased and are a public nuisance, but $4000 call girls are neither--probably college girls with mercenary moral standards.
Spitzer does look like sh*t and fell in it, though.