In case you ingrates haven't realized, touring is a working band's livelihood so it does cut into their bottom line (that means money that pays for their rent, food and bills when they aren't on tour) when they have to reschedule/cancel shows...and I'm sure it's not something that they are happy about doing and they understand how "LAME" it is........
especially seeing what kind of 'fans' they have now who think that just because they've bought a CD, the band owes them everything....it's a symbiotic relationship people....
and being someone who has just finished dealing with a bunch of immigration shit, it doesn't matter how far in advance you submit all of your documents, if bureaucracy decides to take it's fuckin' time, it will....and all you can do is sit by and wait....so it's not their fault the visas weren't issued on time....