Culturally Speaking why do people think Hip Hop?

Why do people think only Hip Hop talks about drugs, money, killing, , & using the word *******? Not that all Hip hop talks about that stuff and not all rappers use profanity or they N word like Lupe Fiasco. I don't really listen to hip hop but I do listen to A LOT of metal & a lot of metal talks about drugs, suicide, killing, , satan, hell, devil worship etc.