Few professional photographers will touch concerts with a barge pole. Hundreds of kids who would like to break into photography shoot concerts for free, some of them are better than others.
I've known a guy who complained about that exact thing. He said he used to get invited to a lot of gigs, take decent photos (i hope he won't mind me sharing a link to an example that i quite like), and got paid decent money.
Then a few years ago, that all changed, kiddies with new cameras were promising to take photos just to get into the gigs for free, and his work dried up. Ironic thing is, that now he's getting more invites now, because those kiddies had no talent, they were 'just fans' (to quote from Almost Famous) who wanted to see the gig free, and the promoters have realised they have to pay for really good work...