It is an answer short on patience, but it was a comment short on insight. In response to a post relayed in short as: ‘The common definition of rationality is stupid. Here is a new proposal that is a basic tenet of most of my writing. (Implicitly, keep this in mind when you see me talk about rationality.)‘, the poster simply added ‘Well, I think the original definition of rationality is right, and I’ve said this before.’
The inciting comment seems just like the responses (on Fark, HNews, etc.) to Pullum’s article about Strunk & White- people who like what they learned flatly deny any counterargument.
I’m in a similar situation—I comment (sometimes) on reddit and HNews, and have occasionally posted a few sentences to OB, but I am much less likely to comment here. The high quality of the posts and comments leads me to agonize a bit overmuch about every part of a comment, and sometimes I will write, edit, and rewrite a comment before deciding to just not comment at all. I, too, often feel I would not be contributing anything original.
(I should also note in this comment that I am male.)