Overall, commenters seem to have had fairly positive things to say, but a number ended up arguing against points I wasn't making. To be clear: I don't think RMS is wrong to argue for Free Software, or that he should somehow moderate his position; I just don't think mentioning 9/11 or the Swindle is particularly helpful to the FSF cause. If you haven't yet, check out the recording of his talk and judge for yourself.
Finally, I'm incredibly grateful for all of the contributions RMS has and continues to make, but I don't think RMS (or anybody) is beyond criticism. To equate criticism of a tactic with criticism of an ultimate goal does not seem to be an effective way to encourage feedback or open discussion. I'd love to see an FSF which takes itself seriously through its spokespeople and campaigns, because I think a cohesive and credible argument from the FSF is an important part of the discussion about the future of technology's role in society.
Alright, that's enough buzzwords for one paragraph. Thanks for taking the time to discuss, everybody.
[Edit: here's the original letter]