Waxing indignant: pointless?

In the comments to a post I have up at Aetiology discussing the recent XDR-TB case in the U.S.,, Scott suggested that bloggers were putting too much emphasis on whether the TB patient was stupid/arrogant/self-centered/whatever, and later that “waxing indignant is pointless.” I started this as a response to those comments, but thought instead it might be an interesting conversation to have–is such indignation pointless? Certainly indignation about this guy’s behavior won’t change what’s happened. Indignation about creationists’ abuse of science won’t make them stop or change their mind. Indeed, some would suggest that even mild rants that don’t necessarily outright insult an opponent still hurt our cause in the long run. So, does such indignation have a point? If so, what? What do you think? Feel free to comment here; I have my own thoughts on it over at Aetiology.

[Edited to add: while the TB story is what spawned this musing, don’t limit it to that…certainly we here do this a lot with creationists and science teaching/literacy in general as well, so feel free to address those topics too.]