I'm sure if people insisted on using racist or sexist language because it's "just words" or simply because they can, you would be offended and uncomfortable.
Can you explain to me how swearing is analogous to racist and sexist language, and in particular which entrenched power imbalance dynamic is in play?
If you get into a train carriage and there's a group of men swearing away and you know you and everyone else are going to be stuck with that for the duration, do you challenge them and ask them to tone it down? Do you try and "keep it real" and laugh it off? Or do you just let them claim the space and suppress your disgust?
I have no idea what 'keeping it real' involves, so putting that aside...
It depends. Are they swearing away quietly and appropriately to their environment, in a manner that does not intrude upon the journeys of others, in no louder tones than other conversations happening, and moderating their language if there are children present? Or are they being loud, boorish, and antisocial?
In the former case, I dare say I'd not notice. In the latter, I'd dea with them in the same way as I'd deal with any people behaving in a loud and intrusive way on public transport. First, assess the level of risk and if the risk was acceptable to me, ask them to tone it down.
Again, you are conflating 'people who are behaving unpleasantly' with 'people who swear' into a single category. Which... no. Quite a transparent approach argument but still failing the logic test.
I'm still no clearer why a group of adults should stop swearing on a forum for adults where swearing is generally judged to be acceptable.