Yes, I'd agree with that, janea, at least up to a point. I suspect that many habitual swearers (the ones who litter everything they say with fucks) started out knowing that their speech was offensive but who, because of the perople they mix with, become habituated to it and don't really think about their diction.
I think Roache is talking about your average swearer, who uses swear words discriminately rather than indiscriminately, which is what you're describing. I can't actually say whether I find such indiscriminate use offensive because I can't actually recall ever hearing anyone talk like that. I imagine I would find it tiresome and 'ignorant' rather than offensive, which probably makes me a bit of a language snob!
Or perhaps a dictionist or language-ist!!