I also enjoyed the talk- I've noticed (based both on the behavior of others and on my own behavior in the past) that there is a great temptation to, well, be a dick when it comes to disagreeing with other people. This gets justified by saying "well, you have to have shock value to get through to people," or "we can't be seen as being weak/accomodationist," when in fact these are just rationalizations for being a dick because, let's face it, sometimes it feels good to be a dick. There can be something strangely enjoyable, almost therapeutic, about getting out one's anger, proving to ourselves how clever we are, etc., and it's not surprising that people who did this justify it by trying to claim that it is the most effective way of getting through to people (besides, I think at times we are all tempted to take up extreme views). I think that much of the disagreement with Plait on the part of skeptics who criticize him for being "accomodationist," etc. are those who enjoy being dicks and try to rationalize it by thinking that that is somehow the best way of getting through to people.
But what it comes down to, as Plait pointed out, is that any time we're trying to communicate an idea, we need to be mindful of what our goals are- if one's goal is to really get through to people, then being a dick may not be the best approach.