Many of the readers may in fact be white nationalists looking to Moldbug for justification for their ideals, and I'd speculate the post is written how it is because it's just not helpful to tell them their concerns are flat-out invalid.
I am not here to defend this position, I am simply here to say I find it to be something other than indefensible.
On the contrary, it's impossible to reach that conclusion if you read even cursorily. For example, neoreactionaries generally accept the results of mainstream academic studies concluding that Chinese are on average more intelligent than Europeans, and that European Jews are on average more intelligent than European Gentiles. These are not views traditionally associated with "white supremacy," to say the least.
P.S. +1 for the reference to one of my favorite sly Simpson's jokes.