Representation does not imply being "based on" said matter. A sci-fi game can still absolutely include non-binary people, especially one with these many characters (yes, there are lots of NPCs in the game), without being strictly about gender politics or any less a sci-fi. It's sort of what science fiction as a genre does: touch on social, political and existential issues through the lens of technology, science, speculative futures and the likes. This itself is a pretty big talking point in the current socio-political landscape, so it'd make sense to touch on it.
Secondly, no one is "forcing" anything onto video games. No one spoke of non-binary inclusion as a demand here, and rather as a speculation on their inclusion or how they'd fit into the setting - heck, I've made the argument that their complete *absence* could make sense given how relationships and gender are shown in the setting to exist only because it's a means to ensure a new generation of workers for the Board, and not because the Board cares about human relationship or identity per se. If anything the only one here who seems to be wanting to force something *out of* video games is yourself, with this post of yours. The only one being "selfish" here, demanding the exclusion of a very real demographic in society, is yourself.
Lastly, you're going about your demands the wrong way. "What about wheel-chair bound people? Or people with prosthetic limbs? Or blind people walking down the street using a walking stick, or an assistance dog?" Yeah, why *don't* we see more disabled people in games? Talking about the potential inclusion of one minority doesn't preclude the potential inclusion of another - I certainly wouldn't mind seeing the presence of people who are impaired in any way, especially in a setting that makes pretty constant references to worker accidents and misshaps, and where such accidents and failures in workplace safety are placed on the worker opposite to the company. A side-quest dealing with such a scenario would have been very fitting to the game's setting and very interesting as well. Your argument is similar to the sort people who work 60 hours a week on minimum wage use to discredit the very real complaints people who earn more or work less than they do have regarding work times and salary - the question shouldn't be "why should they ask for better working conditions?", or in this case "why should they get representation?", and rather "why aren't we asking for the same?".