It's funny you bring up Trek. A lot of RPG's follow the Trek style of races. You have the Fighty Race, the Smarty Race, the Funny Race and then you have the humans who come in every stripe.
I think this is what the blog post was referring to, albeit in a rather highbrow, longwinded fashion.
Mono-culture races in SF and fantasy are pretty much a staple of the genre. To the point where the exceptions are notable simply for being exceptions. Sure, as the game of D&D expands, you get different takes on races. But, never (or at least very rarely) within the same setting.
Yet, in almost every setting, humans are the dominant race, and almost universally the most diverse.