I don't get why people are chatting on about Eminem being a hip-hop act and taking away from rock/punk/indie roots or whatever.
Eminem - the most 'liked' artist on Facebook - with his recent music to this huge crowd, is a pop booking, not a hip-hop booking.
And RandL? Bar Glasto, it's the biggest festival in England and the one most teens attend and it's catering to that crowd.
Plus the focus isn't even on the music at RandL anyway.
As people have said, the 'proper' rock acts booked for the main in recent times haven't even done well.
I think some people are apprehensive to seeing a man rap to such a huge crowd. But the thing is, acts don't need to have a traditional live instrument set up to get a crowd going, seriously. The best hip-hop performers have that charisma to bring a real show. See: Jay-Z. I'm pretty sure Eminem can bring the heat, for the pop crowd anyway (who will have been drinking all day and know and recognise all Em's biggest hits anyway whether they like it or not so they'll be hyped.)