And Scotty! Right?
Oh, wait... I forgot, Scotty is in a relationship with Keenser (which I guess doesn't count as gay because Keenser's gender hasn't been explicitly defined).
But why not Scotty?
I left off Scotty because of a rumor regarding his character development in the movie that I didn't want to get into.
And I heard that Uhura and Spock might break up, so why not Spock or Uhura? Maybe McCoy's divorce was because he fell for another man?
Or why not Kirk? This is a guy obviously (in nuTrek) compensating for something.
You could theoretically do all of those if you wanted to and were willing to show how it developed from their prior heterosexual relationships.
But then you have Sulu's character who has had no attachments shown in the prior two movies which makes him an ideal choice for further development, both as either a gay character or just in general.
And how do you define established heterosexual relationships if you are so dismissive of anyone pointing out Sulu's established character? Seems like you want it both ways to justify this.
What both ways? The other characters have detailed established relationships in this universe, while Sulu has vague lustful googly eyes and remarks in a completely different universe. The two aren't comparable, but even so, I'd be fine with the others if they did the work to justify it. Sulu however is a tabula rasa as far as relationships go in this universe, so why not take the open option that's in need of greater characterization anyway?
Honestly, my biggest problem with this is that they assign this to Sulu because of George Takei. I have friends who are actors who wish to be who they are IRL and yet still be taken seriously when auditioning for whatever part they want to play. This could cause issues for actors getting roles if their off stage sexuality might overshadow their on stage characters.
Except we're talking about John Cho, who is straight, playing a gay character. Alongside Zachary Quinto, who is gay, playing a straight character. Soooo, yeah, I don't see people playing outside their own sexuality going away anytime soon. This also seems like giving this minor secondary character change way more power and influence on Hollywood casting decision than it actually has.
And as many times as people want to say it, the decision wasn't made primarily because George Takei is gay. There were several reasons given by Pegg for why this was a development they wanted to do for the character in their own right absent of any connection to Takei.