I'm pretty sure Eliezer is consciously riffing on some elements of the megalomaniacal supervillain archetype; at the very least, he name-checks the archetype here and here in somewhat favorable terms. There are any number of reasons why he might be doing so, ranging from pretty clever memetic engineering to simply thinking it's fun or cool. As you might be implying, though, that doesn't make him megalomaniacal or a supervillain; we live in a world where bad guys aren't easily identified by waxed mustaches and expansive mannerisms.

Good thing, too; I lost my goatee less than a year ago.