I actually find it quite interesting that escape artists products in general (so across all the podcasts), and actually pretty much all media, that contains homosexuality in some way, often feels the need to draw attention to the fact that one of the characters is a homosexual.
They frequently don't. You're just noticing it more because we live in a heteronormative society and homosexuality stands out as a result. Skin Trees, for example, didn't really draw attention to the lesbian-ness at all. It drew attention to sensuality that happened to be queer, the queerness is incidental to the sensuality.
I'm constantly hearing this about gayness and it's really a short step from "I wish these stories would just have gay characters without FOCUSING SO MUCH on how they're gay" to "I'm fine with gays as long as they don't SHOVE IT IN MY FACE."
Why does it matter that your steampunk is lesbian or straight or gay or anything else?
LGBT/Queer people live in a heteronormative society-- that is, one in which heterosexuality is implied as default. This can get really stressful. There's the constant battle about who you come out to, because even if you're "out" you are still coming out of the closet to new people as a constant process and you have to deal with those reactions on a daily basis. Harassment is a constant issue, especially if you aren't gender-conforming in your appearance. Getting hate crimed is a genuine worry.
So sometimes LGBT/Queer people seek out homonormative spaces-- that is, spaces where homosexuality is expected and normal. You go there and you're not a minority anymore, you don't have to worry about coming out, and the other people have gone through the some of same shit as you. There's a shared culture that forms around that and it feels safer to be there.
I know people who grew up in the desert with a wide open sky who moved to places where they're walled in by buildings and trees all the time. They say when they come back to the desert, where the sky is huge and the horizon is low, they feel like they can breathe more easily. It's like a weight is lifted off their shoulders and they didn't even know it was there. I'm sure you've felt like this sometime-- coming to your hometown after being away at school, or settling into your house after a difficult trip, or finding a group of people to talk to who get you in a way most people don't. A part of you has come home, and you relax parts of you that you didn't even know were tense.
For a lot of people, it's the same thing with these homonormative spaces. You're safe in a Pride parade, in a gay club, in a Gay/Straight alliance in a way that you aren't in the mainstream community. When you get into those places it's like a weight was lifted from your shoulders, because you're among people who get it.
LGBT/Queer anthologies are just another homonormative space like that. You spend all of your time reading books about straight people, stories about straight people, participating in communities run by straight people. The communities that get created around stuff like LGBT/Queer sci-fi anthologies are ones that are often easier to deal with because there's a shared cultural experience that people understand.
Plus, the LGBT/Queer communities that the lesbian steampunk anthology ends up being part of never have straight people who start threads complaining about how they got some queer in their prose every time the topic of non-hetero sexuality or romance comes up.