I had no idea what was going on with e/em/eir. I have never seen them used anywhere else and thought there was some kind of inside joke on lesswrong, something like a play on the word atheist as a'th'ist, as in someone who doesn't believe in the letter combination 'th', or maybe a bad HTML parser trying to insert a th tag, because they seem to be used where the/them/their would be used. It was bugging me enough that I searched for [space]eir[space] and your comment was the first result to directly address it.

The mistake is assuming that because it works for you it will work for others.

Yes, I erred in thinking that others perceived writing the same way I do. I should point out, though, that you erred in thinking that my claim was based on a simplistic model of reading, rather than what has actually been proven to work, albeit in my limited "data set".