You know what? I have always been afraid to use vulgar words even as a kid. When I was 10, I first use the f word (without knowing it's definition ofcourse) and someone told me, "Do you know what you just said?" and I replied, "No." The person said, "Then don't say it."
When I was a kid, there were a lot of things I wasn't supposed to do or say and I was like, "Why?" and I would think, "What's the difference if I curse in my head? Will that still be considered a 'bad' word?"
Why do people curse anyway? For emphasis! I think that's why rappers use bad words. Not necessarily to be cool but sometimes, there really is no other way to express anger but to use vulgar words. But then again, what would you gain if you do say them? You're only offending people. And yes, who cares if you offend people right? But what if someone offends you? You wouldn't like that feeling huh?
People have a tendency to forget that words have power. Because we have been bombarded with profanity every second of our life, it becomes second nature to us. And men are creatures of habit. Once they get used to something, they become lazy to change!
The English language is composed of about 5,000 or more words (probably more), why not utilize it? If you are angry and are tempted to say you-know-what, why don't you say, "I'm furious at you! I'm livid!" And watch how that person reacts! LOL They'll probably be even angrier because they have no idea what you just said. Ignorance isn't bliss; it's ignorance.
In the end, it all boils down to this: treat others the way you want to be treated. The Golden Rule. An old adage but still very useful.