Just going to step in here and disagree with basically everybody right quick, please don't hate me to much.
I would caution the game maker to make more non-normative games so that people see more variety and get to experience different types of characters. Flood the market with that **** and make them play cool-ass games that change their opinions (or else complain eternally about all the cool-looking games they can't play because eww teh gays omg what can play nuuuu :tears

. Frick them.
Eh, there's a pretty significant difference in shoe-horning sexuality into a game and gameplay mechanics that make the mc out to be a badass. It's more than just whether a character is gay, bi or whatever for most people but how they are represented. We're at a point right now where diversity is the newest fad, and while I don't have anything against a diverse cast of characters, I don't like seeing my deep political/war intrigue game series that has always had a diverse cast anyway suddenly turn into LGBTCQ saves the world while nattering about their sexuality non-stop along the way.
Don't get me wrong, diversity is fine, and I'm definitely a fan of your previous comment about having gay/bi/whatever characters in your game that the player may or may not ever realize is anything other than what their default perception is. I have no problem with them being in games, I just don't want to be forced to engage in gameplay about sex and sexuality in a game where it serves no purpose other than to "Make them get out of their comfort zone" or whatever. People have lots of reasons not to want to play that kind of stuff, far beyond just being bigoted.
Personally to me its that I view participating in virtual relationships and such as a form of cheating, that's just my opinion and I feel I'm entitled to it no matter how many people may call me backwards or bigoted for it. If you want to make a game about relationships then make one about relationships, I don't understand how people think that shoe-horning in 'surprise dating sim gameplay' and the like is supposed to change anyone's opinion though personally. It just causes me to take a trip to gamestop. If that's your vision, fine. Market it as such and your audience will find you. If not, to me anything more romantic than FFX in a game where the pc is meant to be an avatar for the player is a bit underhanded, make it optional please.
Not necessarily.
For example: I have played several games in the past where I really enjoyed the game play. But what would have otherwise been an enjoyable play experience was literally ruined for me because I was forced to play as a character who's personality I could not stand.
I have always believed games needlessly turn off players by forcing players to role-play as certain in-your-face personalities that may or may not agree with the player. So to me - that's just an unnecessary risk if you are going to invest so much of your time and energy into a project as draining as creating a video game.
I'll never understand that argument, probably because I came into video games late in life with a lifetime love of reading. There are so many different beliefs and viewpoints in this world that the idea of avoiding personality traits is just silly. You can respect a character and his/her struggles without having to personally agree with everything they do. The only caveat to this I'd say would be where the player character is meant to be nothing more than an avatar for the player but then is forced to choose one way or be talked down to for 'making the wrong choice (Inquisition, anyone?)
Books have gotten away with this for decades, why not games? Characters can be likable with any number of unlikable traits, people are all different. I love and accept my wife but that doesn't mean we don't have vastly divergent opinions in some area or another. It's not what a character is that should bother you so much as what is foisted upon that character merely for 'the sake of (insert agenda here)'. With purpose and distinction, even a controlling, genocidal maniac can be an endearing character. (Delita Hyral, Final Fantasy Tactics). So arguing that LGBT characters can't is just plain silly.
If you want to make a game that has a protagonist who makes a point to describe his or her homosexuality you are going to turn off a significant amount of players. That is just a fact.
It may not bother you, or me for that matter (it wouldn't by the way). But a game-maker must decide what is more important. Is it appealing to a broader audience or is it making the player role play as a homosexual. That's why I advised caution - because I think those are important considerations to weigh.
We're all indies here anyway, so while there is a grain of truth to all that I'd say it's not really worth worrying about to much. It all boils down to the developers own personal vision, I believe if you are honest with your audience than you will find an audience no matter what your vision is. It's all the shoehorning in of different opinions just for the sake of 'inclusion' that I personally can't stand, and I believe that's true for a lot of the other dissenters here, its the feeling I get when my epic action game suddenly turns into "the all-inclusive-bachelor" that makes me disgusted with 'diverse games' not the diversity itself. But try to say that in a game review, and you'll get nothing but hate. The diversity crowd can be just as bigoted and tunnel-visioned as any other group when it wants to be, and that is where I feel most people are grated wrong by the whole movement, as it pertains to games, television, literature or what have you.
Whew, I'm gonna walk away now. In the time it took me to type all this I think there were at least two dozen replies, this topic moves fast. Sorry if anything I said ended up being redundant or already addressed as a result.