The problem I take here is that, if we consider that line of thinking valid, there's just as many, if not more, worrying concerns in a game that does avoid these things.
Even if we're being thorough about removing the above, we're still left with a game that arguably gives the player the ability to commit genocide/murder on multiple occasions. I think the implication of those, on a moral level, are far worse than any swear word ever could. Arguably, much of that is optional as well, but it also means you're restricted entirely to one alignment which kinda goes against what many perceive as the point of a Bioware game.
Sex, swear words, and gore. Those are what the OP wants to be able to toggle off. And you are right, there are worse things--hard, highly addictive drugs (red sand has ugly effects). Genocide. Cold-blooded murder. Vengeance killing. Corpses in various conditions, sometimes piles of them. And if you're not okay with sex scenes, exotic dancers are probably not something you want in the game, but they have been in every Mass Effect game to date. Prostitutes were in at least two of the games and you could sleep with the asari consort in ME1 (not something I'd want to do, but whatever floats your boat).
And the more these things would need to be filtered, the more they'd just be cut out altogether to avoid that overhead cost of censoring in the first place. It wouldn't be some magical free license to make things even more hardcore. Even if the censored parts were made more explicit, there'd be far fewer of them--thus they would feel more like they were there for shock value, and that'd make the game feel less, not more, mature.
I did point out that BioWare tends to make their mature rated games relatively tame, by comparison to some others. And that is true. But others push the limits to what's allowed because they want to shock you and force a reaction. To me, having sex on a unicorn isn't mature. It's about shock value. Shock value rarely has anything to do with maturity. Because BioWare is tamer than that, most of their audience isn't as shocked and thus we're better able to think through what we just saw/did/experienced in their games. And I personally like that.
And again, I understand and respect the OP's opinion, but I think the rest of us would miss out on content if his/her request were to be granted. Even if you dedicate resources to it from the beginning (and this is definitely not the beginning; they've been working on this game since ME3 was finished, if not before then), it's still taking away from something else.