I admit, I feel a small sympathy for Harlan in his initial fumble; it's easy to see how a man of a certain time and place and character might thoughtlessly act thusly, and I don't judge him quite the same way I would if, say, Jed did that to Susan at the Hugos. (It is to laugh at the very thought, and perhaps that's a reassuring measure of how far we've come.)
But at the same time that I sympathize with Harlan's action, with the way he was conditioned to such actions, I also think that all of us, however subject to our own cultural conditioning we may be, should be able to rise above that conditioning. We must be able to admit, in the cold light of the next morning, that our pre-programmed sexist/racist/etc. behavior is a relic of an earlier, brutal, age. If we are not to be condemned as brutish relics ourselves, we must repudiate that monkey behavior.
We must uphold the standards of civilization, even if we sometimes (inevitably, all of us) fail at enacting them.
Harlan's offense was neither the first, nor the worst. But it was symptomatic of an ongoing difficulty in the field -- one that has had women confiding in me on the point of tears -- and Harlan's offense was very public. So he draws the fire for a larger category of problem.