There's two different types of swearing:
-Swearing to insult or attack someone
and
-Swearing because your character would
I do the latter half quite often, my junker captain has the vocabulary of a trucker. Things like:
"Bloody xenos!"
"Damnit, this scrap field is bone dry."
etc.
Even my order character occasionally swears at the npcs around toledo "Damn bounty hunters are persistent today" etc.
Swearing to attack someone, like "$&% you! Why'd you shoot me you $&%*ing #&$%%#" is not ok. You're using it to verbally attack someone (and it's out of character/RP, on top of that).