I've never heard more different explanations for anything parents tell kids than why they shouldn't swear. Every parent I know forbids their children to swear, and yet no two of them have the same justification. It's clear most start with not wanting kids to swear, then make up the reason afterward.
-Paul Graham in The Lies We Tell Kids
This sounds like a challenge. Would you prefer your children to not swear; and if yes, why?
My reasoning would be that I want my children to be successful (for both altruistic and selfish reasons), and I believe that a habit of swearing is on average harmful to social skills.
Disclaimer: There are situations where swearing is the right thing to do, so it would be optimal to swear exactly in these situations. But it would be difficult for a child to determine these situations precisely; and from the simple strategies, "never swear" (which often develops towards "don't swear in presence of adult people or someone who would inform them") seems very good.
Here's the new thread for posting quotes, with the usual rules: