Swearing at children is relatively unusual.
I wish, I wish, I wish, I could agree with you. I can't. If it's your experience, you just live in better places.
Really normal in my childhood, alongside plenty of violence, and decades on it's been really normal with many crap parents every decade of my life. I'm glad to say levels of general violence seem to be lower.
I grew up encouraged to swear as an alternative to crying, considered far worse, but not if the pain was caused by a kicking.
We had exactly what kind of dregs we were screamed over us with foul language, and while school and eventually 'care' used different forms of negative language, they re-enforced the idea that we had no value and our existence was a problem to all. The cursing wasn't really the big issue in hindsight.
V. little sound proofing here, neighbors with kids I have to hear every word from:
MC couple who don't swear but shout all day every day, at their children for what they haven't done, have done, or for crying when shouted at. Yelled at that they are horrible, weak, whiny, children constantly, for what seems like normal childrens stuff. They aren't under the standard stresses, just don't seem to like them most of the time. No swearing involved, but so painful to hear. We're the only people here DC's are allowed to speak to.
A totally non swearing, but vindictive, angry, loud, controlling 'you have no right to hold anything but my extreme opinions and views' parent, whose DC's are beyond oppressed. Told they're hated for their race. No one knows what they think as they're silent or monosyllabic. Loudly lectured about what they must believe and think, and berated for failing to nod acknowledgement in the right places. Outside she speaks for them, everyone says they're so respectful, and she laps up the conformation of her parenting.. They aren't allowed to speak to us or anyone. No swearing, but edges of Prevent, but, she's also trying to keep them alive in post code gang land.
Nasty violent, bullying, swearing mother, at war with her alternating baby daddies, whose kids have grown up similar. Backed up by an XL Bully. Screams abuse at home and on the street, kids are either screaming it back, or the lot of them ganging up on neighbors or passers by, sometimes physically. It's a long lost cause. We all avoid other than when forced to engage.
Plenty of similar on our block and it generally gets scary in summer when they, outdoors, later evenings, and alcohol, combine.
We're cheek by jowl to nice bits and MC lives but quality of life has got way worse since Sure Start, community center, youth club and outreach closed down.
Afraid I'm naturally sweary, withholding it. My Dc's knew why I tried to keep it from them, and why I was trying to raise them differently. No one here's allowed to swear in front of anyone under 18 unless it's me having to big up against aggressive neighbors. I'm visibly disabled as is one DC, so attract some choice descriptions, and being able to hold your own affects what happens next here. Being generally polite (= a snob and victim) but able to match the vernacular powerfully at will can actually stay violence. We code switch as necessary.
Because of how life is here, conversations about what swearing is, what it's uses are, and when it may be appropriate and not are part of education and all mine could give you an academic essay on 16th C swearing onward. Like many, I'm doing my best in the circumstances I have, rather than how I'd like life to be.