Mainstream rappers usually swear because they're trying to be edgy and they have nothing better to write for the bars. Same with most mainstream swears, more or less the edgy part. Swears are usually just expressional, and are used because it's natural for the artist to say a swear at that time, or they might need a couple of extra syllables. That said, I see most swearing as a lack of creativity. People swear because they have nothing else to say, it's a filler word. There are many more creative things you can say than saying the f-word every five minutes. Explicit isn't that bad, half of the stuff I listen to is explicit. And also, my parents cuss all of the time, the only reason I can't is that I'm a kid. Once I'm 18, my parents really don't care what I say.
