Why should they be excluded from a society that supposedly embraces ALL diversity?
Nobody said anything about "excluding." The point is that there are already plenty of those included along with everyone else, so there's no sense in claiming they're somehow not represented. Indeed, white heterosexual males are greatly overrepresented in Trek compared to the real demographics of the human race, just as they are in most television series, so it's downright ridiculous to claim that there aren't enough of them.
Especially since we've already got PIke, Kirk, McCoy, Scotty, Picard, Riker, O'Brien, Paris, Archer, Trip, and that British guy on Enterprise whose name I just can't come up with right now . . . .
Reed?