I think he is a bit hesitant to incorporate these stuff openly because he thinks that it might be perceived as tokenism. Do I have it right u/mistborn ?
Edit: If Mr. Sanderson decides to show up; the deleted comment was about you mentioning one of your characters was gay but he didn't get a chance to date anyone yet therefore it is not really out there.
It's partially that, certainly. But in the case of Bridge Four, it's more about the fact that the guys just haven't had time to start many relationships. It's only been a few months, in-world time, between thinking they were doomed to having respectable jobs. Give the fellows some time. Most of the guys, gay or straight, are looking. (Excluding the married ones and the asexual one.)
I hope I didn't offend, it was exaggeration for effect, nor do I think the lack of sexual depiction or even mention is done ham-fistedly, there's always a well formed, even subtle, reason WHY your characters don't tend to be particularly sexual, at least not the major POV characters, be it culture or circumstance, I've just noted that it's something of a theme, which I ascribed, perhaps erroneously, to "delicate mormon sensibilities".
I wasn't offended. I do tend to respond quickly to threads, however, so I know I can come across as terse sometimes. No worries.
By way of conversation, you might enjoy a story from when I was writing the second Mistborn novel. My editor called me one day, and said, "All right. I can't figure it out. Are Vin and Elend having sex or not?" I said, "Of course they are. They've been together for over a year at this point." His response was, "Well, why not say so?"
It was the first chance I had to vocalize something that I hadn't even really figured out myself--something that just felt like the right way to tell my stories. I explained that there were many readers, like my sister, who wanted to be able to pretend that the male lead and female lead in the story were going to do things the way she wanted them to, with a level of chastity that made no sense in the culture. There were other readers who would want to imagine wild Allomancer sex happening every night.
In this case (though it may not be every case in my books) I felt it was best not to intrude as the author, as what was going on in the bedroom wasn't plot relevant. In addition, there was a certain...privacy I wanted to afford them, because of Vin's difficulty with intimacy in the first place. I don't know if that makes any sense or not, but while Wayne's sexual exploits can be front-and-center, it felt specifically wrong to go into Vin and Elend.
That said, I'm totally a prude. The Daenerys chapters from A Game of Thrones, for example, were too much for me, and are a large part of why I didn't continue with the series despite thinking the first book was very well written.
You should go listen to the Writing Excuses episode we did where we interviewed an erotica writer on how to write sex scenes. Mary spent basically the entire episode poking fun at me. (Though I'd like the record to stand that I was NOT blushing as much as she implies on the recording.)