There is a mechanism for having a conversation between two people, but it isn't the comments, it's the private message system. If Annoyance's intended audience was exactly one person and no one else was meant to be able to understand him or get anything out of the comment, then why was it here and not there? Pure convenience?

Advanced mathematics is the sort of thing that a lot of people here know about; I stay out of such discussions partly because they rarely pique my curiosity and partly because I am aware that I am below the threshold of what could reasonably be expected in the way of mathematical expertise in this context. Most of the people here know vastly more about math than I do, so I don't expect people to keep mathematical discussions down to my level (although I'd probably leave the blog outright if such discussions came to dominate, since I would be unable to glean anything useful). Unless something has greatly escaped my notice, no highly specialized knowledge of genetics is commonplace here (or at least not more so than in any gathering of generally bright people).

Combined, the fact that it was posted publicly without any obvious earmarks of being intended only for gwern, and the fact that I don't think I am unusually poorly informed about genetics, led me to believe that Annoyance was aiming at too high a level of expertise (or possibly just being cryptic, irritating, and patronizing). The upvotes on the comment in which I said as much suggest that it is likely other interested viewers would also like to know what is being said. (Either that, or they just don't like Annoyance for some reason.)

Consider a similar (hypothetical) situation where folks are having a conversation involving some advanced math, and you come along and berate them for not including explanations for those that haven't been exposed to it before.

Did Alicorn ask for explanations? Why do you think this has anything to do with explanations? Was the conversation remotely like that? Have you read the conversation? How do rhetorical questions make you feel?