I don't hold with this "lack of vocabulary" argument. It's nonsense.
To paraphrase Billy Connolly, if you can give me a non-sweary equivalent to "f*ck off" I'll gladly use it. And it certainly isn't "go away."
That said, I agree, people swear too much, myself included. I think though there's a difference between swearing and inappropriate swearing. I'd be happy swearing like a navvy in front of my mates, but I wouldn't do it in front of my mother and I dispair when I hear people bellowing it to each other across the street.
I'd agree with the point Toys made too; broadly speaking, you choose to take offence, not cause it.