This issue has hidden complexities when viewed from a social science perspective. I hope I do not disrespect anyone in my trying to share my personal thoughts on this issue.
The conditions that lead to an outburst that contains aggressive language or cussing often happens when an individual feels suddenly trapped or surprised in an unpleasant or frightening way (i.e., if they feel their life is threatened). This kind of language at moments such as this can be forgiven, without being condoned.
If children feel like they are living in a world where their backs are constantly against the wall, I think we can certainly expect to find greater instances of distressed and aggressive language being spoken by them.
I think we would find fewer examples of children using vulgar or aggressive language if they felt they lived in a word that was safe, and among community members who cared about them.
For the sake of their children (and for a more peaceful and civil society),
I would hope parents would not gratuitously use swear words, so that the child becomes socialized into thinking that casual use of these words is appropriate.
In regards to art and culture: freedom of expression in a free society dictates that we must tolerate aggression and swearing within the context of art.
Consequently, I hope that artists maintain an awareness of the role of aggressive language within the context of their art. The artist should be in service to the greater message they are delivering; maintaining an awareness that art should aspire to educate, reveal truths, and provide original new perspectives on the human condition, rather than engender a sinking into a trough of nihilism and vulgarity. (Image courtesy of www.independent.co.uk)