Why should it matter to society what the difference between the two is, if the better of the two is still bad enough that they should be hung by their toenails and beaten to death with a sack of hammers?
After a certain amount of bad, there's not much you can do to punish it.
What reason do we have to discuss the difference, unless you think a 30 year old fucking a 17 year old is redeemable?