I know someone who generally does not swear directly at people, but uses swear words profusely when angry and believes it is unreasonable for anyone to judge them or have negative feelings about this, because it's just words and they aren't swearing AT people.
A few years ago, they went to a fan event here in Japan hoping to buy multiple copies of a zine for their friends overseas, and when told they could only buy one copy, they stood in front of the stall and cursed profusely in English out of frustration. After the event, they found that the Japanese side of the fanbase had unfriended them and removed them from online communities because of their outburst. They were completely blindsided by this. (In fact, their version of the story was just, "I went to an event in person and after that everyone unfriended me, I don't know why they're like this." I only heard about the swearing incident from a mutual friend.)
Anyway, there's obviously degrees and nuance here but I think people who swear profusely-but-not-at-anyone-specifically don't realize it still sometimes comes across as hostile.
A few years ago, they went to a fan event here in Japan hoping to buy multiple copies of a zine for their friends overseas, and when told they could only buy one copy, they stood in front of the stall and cursed profusely in English out of frustration. After the event, they found that the Japanese side of the fanbase had unfriended them and removed them from online communities because of their outburst. They were completely blindsided by this. (In fact, their version of the story was just, "I went to an event in person and after that everyone unfriended me, I don't know why they're like this." I only heard about the swearing incident from a mutual friend.)
Anyway, there's obviously degrees and nuance here but I think people who swear profusely-but-not-at-anyone-specifically don't realize it still sometimes comes across as hostile.