I enjoyed your post. It gives some validity to your claims that censoring in this case might be justified (although that is not necessarily your claim).
Code makes an excellent point (or at least what I got out of it), and I think that you do as well.
Here are my thoughts on the issue.
I do not believe that bad words hurt children. Knowledge of a bad word, or use of it does not inherently change the child for better or worse. But what it does do is affect the parents that believe that children should exhibit innocent and angelic qualities. When children swear, it is not affecting them or their peers. It offends the parents that believe that children should not say those things.
Saying "stupid" does not harm your children. Hearing them say it does harm your sensibilities. It is important to distinguish that (although it is still a valid complaint) you are protecting yourself, not your children. Especially since they will eventually say "stupid" in the near future whether you like it or not.
I realize that children of any age are going to be exposed to things you may not approve, but by discussing it in an age appropriate way and pointing out that you do not approve, I feel is more beneficial than even editing out such things.
I completely agree with you. Discussion of the issue is the best medicine. After all, it isn't the words
that these adults are finding so offensive. Good topic.