Ignorant? He probably read more old books than you -- which does not mean he understood much. He spent 7 years of early retirement burning his dot-com loot on Amazon.
History grad students have to TA. They have to produce research. It's hard to consume as much as Moldbug when one has such demands on one's time.
More importantly, Moldbug almost certainly has more brainpower than the vast majority of history grad students. Whether he used such brainpower wisely is highly debatable.