I'm intrigued as well, is it because it's attached to a religion or is it the manner in which it's killed?
FWIW, as far as I know the slaughter in halal butchery is with a very sharp knife, and the animal effectively dies from blood loss.
There would be no pain, the animal merely loses consciousness. Nearly bled to death myself once, admittedly without a cut mark to the neck, but it's just like slipping into sleep.
Traditional methods are - AFAIK - to stun with an electrical prod and then shoot with a bolt gun into the brain. Is this method 100% accurate all the time, I think I have heard that it's not.
Meat is meat, it has to be killed to be eaten.
If meat served for consumption can be eaten by all faiths, kosher and muslim is the same method, and christian or other can eat either without any compromise to anything, then I too really do fail to see the problem.