Why is a character "presumed straight" according to you when no sexuality is mentioned? As long as sexuality is not mentioned, a character can technically be anything. And even if it is mentioned, that's not a guarantee. Even if a male character has a son, he can still technically be gay, but tried to live as a heterosexual sometime in his early life where he got his son, for example.
These are all fictional characters, and anyone can make up whatever background they want for them. You love to presume a straight default because it enables you to victim-play for the LGBT community. I guess you subconsciously do know that heterosexuality is in reality the default, and the rest are.... Divergent. Yes. I said it. Heterosexuality is the biological default of a species, because sexuality is first and foremost a method of reproduction, and without heterosexuality, the species goes extinct. This translates into a cultural default, of what people are generally willing to see and aren't willing to see. You can try and create a culture that goes against biology, but ultimately, it will lose, sooner or later.
That being said... For me things are simple. Anyone is free to do what they want with their own life, as long as it's not imposed on others. That means, the default can be presented easily, while the divergent aspects, unless made for that specific divergent audience, will always be an imposition from the divergent on the default.
See above, regarding the default and divergent perspective. Additionally... I have to ask... What's the limit here? Next thing we'll have to accept looking at people making out with children because pedophiles also want to be included.
As previously mentioned;