Give me one, just one, solid reason why any band wouldn't want to go to a country where they speak the same(ish) language, the people are generally friendly, and where there is a fanbase they have visited before, which is eager to see them? A country where even walk-up sales, and the resultant CD sales, could be significant, and where getting airplay on a local radio station would give more exposure than a national rock show over here in the UK? Just ONE real reason, not just "they don't wanna" (typed with your bottom lip sticking out like a fucking 5-yr old).
Now I don't know the actual reason, but there is no doubt in my mind that it is a genuine reason, not just that they don't give a fuck about it. Mentioning other bands you have seen lately has fuck all to do with it, every band, every person entering the States is different. Once upon a time, back in the 80's you could almost bullshit your way into the US by just turning up at the airport, today is a different ballgame - think back hard now all you Merkans, maybe try to catch up on International news......(Hint, that's to do with those blobby landmasses round the globe AND your fine country)
As has been said before on here, there are many many reasons why US Immigration might decide to turn people away at the airport, for example, if someone has EVER been arrested etc, and that's what they decide when you get there. Trying to sort out paperwork in advance is even harder, a real minefield. Maybe the band don't have the right people working to sort out their paperwork, but, getting rid of them might be tricky - it could be someone's wife/girlfriend/brother, I don't know.
Not that I want to get drawn into a slanging match with our Transatlantic friends, but you really need to understand the universe doesn't revolve around you, your country is harder to get into than erm, something which is very hard to get into, at the best of times, even for those of us that WANT to come and visit you. Perhaps we can have your names and addresses and you can sponsor our visa applications?
Toodle pip!