Getting here late, but uh, my 2 kroner.
I create characters that fit the story I want to tell. I do the research I need to, in order to get the basics right. I don't sit down and think long and hard about their skin colour and culture because I am not giving a presentation on it. I'm playing a person. Even when I play literally a white guy whose home address is 10 minutes over from where I live in real life, he's nothing like me. Different experiences shape different people. There are no two members of any ethnicity who are the same, have had the same formative experiences.
I love seeing diversity. I hate diversity taking priority. Play the character you want, and if they're a member of a different nationality, ethnic group, gender or sexuality of your own (and you want to make this an issue in the first place) do some basic research, avoid the most obvious tropes and clichés.
There's a writing exercise I recommend if you're in doubt (like many others here, I am a writer). Write your story with every character as a white male (or whatever your default is). Then roll dice for gender, ethnicity and sexuality. If doing so fundamentally changed your story, then you're not writing people but tropes. Obviously works best in a setting with at least some equity.
On the subject of characters getting hit up for the horisontal mambo? Never happens to me. My characters tend to stay single for the duration of their run. I am a slow burn kind of player, and I think I give off a very obvious vibe that I'm not interested in RP relationships that last three days at best. I use a male top model for a PB on two out of three games so it's not about the looks. Have seen old, disabled, pointedly not attractive characters get pounced on by hornies (yes, old and disabled is considered 'bad' by a certain demographic. I am old and disabled in real life, I get to say it). It's about the way you act, talk, and signal.
And then of course there's that demographic of players where the only thing that matters is that your character has a pulse, but that lot tends to get bored and wander away from me after about three minutes of me pretending not to notice their cleavage or long eyelashes. I am not displeased with this.