"I think that the use of swear words demonstrates a lack of command of the English language" oh *that* old chestnut !
I agree with what Stephen Fry says about this, many many people who use four letter words have a great command of the English language and - I might add - often use so called 'bad language' rather poetically if well placed.
I think swearing is a) a healthy release during times of frustration or pain and b) can add gravitas and emphasis to the English language in a unique way.
IMO children should be brought up to know when swearing is 'appropriate', ie. to be able to control/kerb it when in mixed company or in public.
I got a clip round the ear for swearing unnecessarily when I was a child, I believe I know as an adult when it is or isn't appropriate.
My family and I are 'free range' with our four letter words when we get together and most of the time, they are used humerously.
For the above reasons and more, I have real issues with the control of peoples' so called 'bad language' - in real life and online, within reason of course.