At this point it seems to be less about convincing devs and more about keeping from being shouted down by all the naysayers.
To be fair, so far the request is, "Because I want it" without any other reasoning. It doesn't fit the theme of the franchise. People who consent to sex rarely, if ever, have sex with their underwear on. Soldiers in combat (as has been clarified in a previous post) often use profanity. Soldiers in combat generally are required to kill. It's not just that it seems technically difficult, it's that it's unreasonable because it doesn't fit within the themes of the universe as presented.
If you can give me a reason to implement such an expensive toggle that doesn't involve personal taste, then I'll listen. As it is, yes, I'll continue to recommend people play other games as the theme of Mass Effect clearly does not fit with what they want as part of their entertainment options.