Gender non-conformity =/= rejecting the gender binary, though. The whole point of non-conformity is accepting that interests, fashion sense, behaviourial patterns and types of sexual attraction aren't hard-coded to be rigidly masculine or feminine. Heck, what is considered masculine and feminine greatly differed between cultures and eras, with the modern rigidity being an aberration more than anything.

The idea is that one liberates themselves from the coding of how a man or a woman "should" behave under social pressure and just does whatever they want rather than conform to the notion that their non-conformity must mean they aren't the gender they are. At least, that's how I view it - hence my sometimes bitter remarks regarding the "accepted" perception of the concept that I caught a warning or two for (perhaps deservedly).

Somebody like beholders being hermaphrodites (male-identifying ones, though, apart from the hive mothers?) doesn't exactly serve as a justification for the more "traditional" humanoid races to base their forays into gender identity on. Although, I may have just given somebody an AU/character idea, so there goes that logic.