Moldbug's usage of Brahmin was correct, and Yarvin's usage of Noble is not. An aristocrat is a kind of phenotype, not a culture. You can't become an aristocrat by drinking the right kind of beer, no matter how fervently this is commonly believed. Not even Harvard-brand beer. Nor going to Burning Man.
Under conditions of population growth, the peasants vastly outnumber the aristocrats. The lower classes breed faster. Peasants generate wealth and problems. Aristocrats solve problems. When the ratio decays from (say) 1:100 to 1:200 or 1:1000, problems outnumber solutions and the result is degeneration. America is full of peasants, so it is wealthy and degenerate.
Further, the Modern™ system is designed to deal with this leadership drought. In other words it actively punishes and interferes with aristocracy, because peasant-tolerant systems are incompatible with leadership. Bureaucracy is hostile to responsibility. This means, even if you have 1:1000 aristocrats, you can't solve 1/10 of problems, because they can't be arsed to wrestle the system. They are encouraged to leech off it - it's not like a peasant could stop them even if they noticed the problem. Sipping poolside etc.
Yarvin can call the members of Burning Man [noble] if he wants, of course, as per nihilism. However, they generate problems, not solutions. ¯\_(ツ)_/¯
Progressives are problematic precisely because although they have a few nobles at the top, they are largely composed of peasants. Again you need approximately a 1:100 ratio for sanity, and proggies are more like 1:2000. They can keep any 5% under control at any one time; the rest are on autopilot. E.g. Twitter has Jack and maybe one or two other aristocrats, but 5000 employees. When you're banned it's by one of the thousands of idiots over whose shoulder Jack is currently not looking. Also fun: when a foreign tyrant pokes her head into the dark side of Twitter and demands Trump's tweets get warnings. Then, if Jack tries to revoke this (once he notices), it's like declaring war on this competing tyrant. Let's gloss over the heresy angle, and the fact Jack would dearly like to resign his tyrancy.
Deviancy and deception? E.g. ruining the family so there's more single mothers, who vote left? The peasants can handle that. They have to cause problems but they can choose the form of the destructor.
You can see this particularly in the ""justice"" system. Judge is a kind of person, not a job description. Rightly speaking, the Law is a record of the kind of things a true Judge says. Judges routinely use skills the peasants can hardly even imagine, which render at least half of [due process] a farce. Consequently there are many atrocious judgments entered into precedent. The peasants can't tell the difference. A peasant adjudictor is called a magistrate or something, useful for dealing with routine cases and freeing up limited and valuable noble time. Due to the leadership drought, even if every qualified American Judge was drafted, there wouldn't be enough to populate all the open positions in the ""justice"" system. The compromise is to lie, and Satan loves America for it.
I'm not sure if your classic king's court is due to irresponsibility driving out the true aristocrats, or if it's due to the irresponsibility corrupting the existing aristocrats. Either way the source is the fact monarchy is centrist due to its reliance on coercion. If the peasant can't sell his subject-hood, then the winning move is for your aristos to suck and betray the country.