I have come across the concert debate a few times on the brum reddit page and promoters/organisers have popped up saying that it is common knowledge that Birmingham is a difficult place to sell tickets so some artists just avoid it. I think this is in relation to not global megastars but I always find it interesting. Most people seem to think in relation to the big artists that we're avoided a bit more because Manchester covers the North, London the South, and they think people in-between can just travel to either. Shit for us, like, but good for your Tottenham's.
The problem for a long while was always that the big venues are there (NEC, NIA etc), but the mid size venues aren't. We have one of the best (accoustically) venues in the world in the Symphony Hall, which is medium sized, and does do 'rock / pop' gigs, but it needs to find acts who can command the biggish prices and don't exploit that to play mega-venues.
Talking of Symphony Hall, three of the very best gigs I've been to have been there (David Byrne x 2, Kraftwerk), it really is a phenomenal venue, but I get why it isn't right for all. It's basically perfect for your middle aged types who care more about sound quality and what not more than anything else (me, effectively, and - to co-opt a Stewart Lee joke, the sort of people who go to Stewart Lee gigs).
It will never get edgy acts. The edgiest act I've ever seen there is Belle and Sebastian (awesome btw), which says a lot.
On a side note, going there for gigs has made me a massive fucking snob, I won't go anywhere for a gig if i even suspect the sound quality will be poor.