A lot of people are pointing out that perhaps it wasn't very wise for you to engage with such commenters. I mostly agree. But I also partially disagree. The negative effects of you commenting there, of course, are very clear. But, there are positive effects as well.

The outside world---i.e. outside the rationalist community and academia---shouldn't get too isolated from us. While many people made stupid comments, I'm sure that there were many more people who looked at your argument and went, "Huh. Guess I didn't think of that," or at least registered some discomfort with their currently held worldview. Of course, none of them would've commented.

Also, I'm sure your way of argumentation appealed to many people, and they'll be on the lookout for this kind of argumentation in the future. Maybe one of them will eventually stumble upon LW. By looking at the quality of argumentation was also how I selected which blogs to follow. I tried (and often failed) to avoid those blogs that employed rhetoric and emotional manipulation. One of the good blogs eventually linked to LW.

Thus, while the cost to you was probably great and perhaps wasn't worth the effort, I don't think it was entirely fruitless.