Hm, I didn't feel that Eliezer was being particularly dismissive (and am somewhat surprised by the level of the reactions in this thread here). The original post sort-of insinuated that MIRI was linked to neoreaction, so Eliezer correctly pointed out that MIRI was even more closely linked to criticism of Neoreaction, which seems like what anybody would do if he found himself associated with an ideology he disagreed with - regardless of the public relations fallout of that ideology.
Reminder that the article just said neoreactionaries "crop up" at Less Wrong. Then the author referred to a "conspiracy," which he admits is just a joke and explicitly says he doesn't actually believe in it. The fact that Eliezer felt the need to respond explicitly to these two points with an official-sounding disavowal shows hypersensitivity, just like he displayed hypersensitivity in his tone when he reacted to the "Why is Moldbug so popular on Less Wrong?" thread. The tone is one of "Get it off me! Get it off me! Aiyeee!" If he actually wanted to achieve the "get it off me" goal, indifference would be a more effective response.
If it's worth saying, but not worth its own post (even in Discussion), then it goes here.