Lol, I get annoyed when stupid people say that. I hear it alot.
But I get where they're coming from, cause when they're usually saying that - they're reffering to the rap that they see / hear on TV and Radio.. People like "Mike Jones".
But yeah, the stuff like that shouldn't even be considered Rap in the first place... It's disrespectful cause there's actual REAL rappers out there who actually fall into the rap category.