How long would it take me to persuade you that Bach was fantastic, or that Tosca is an amazing opera, or that Radiohead are one of the best bands out there at the moment, or that U2 write great songs, or that Dylan really is a great singer? People have opinions, the only way you can change someone's opinion is by getting them to listen to the music you like, and hope that they get your message. Music is not about searching through everything until you come to "good" music, you can't simply argue your way into music. I don't particularly like Vai for instance, and the only way you could make me like him would be to play one of his songs that really grabs me, you couldn't argue me into it. Why don't you listen to them about Limp Bizkit (not that I'm suggesting you should, the less people who listen to them the better)?