I've never understood it either. I'm willing to accept that some people get caught up in the moment and go too big the night before: it's a huge mistake, but just that - a mistake. Thing is, at a major airline there's absolutely no penalty for calling in sick. So it seems to me that someone needs to cross two independent gates of stupidity to get to a flight deck while over the limit. You've gotta be dumb enough to go big on a short timeline the night before, then be too dumb the next morning to recognize that you messed up, and follow it with an insistence that "I'm fine" while being fully aware that a phone call to scheduling would pull you off the trip and deadhead you home with no questions asked.
So I come to the conclusion that these folks have problems with alcohol that go beyond what someone like you and I can understand. Most of us are smart enough to not throw away a multi-million dollar career by getting stupid on an overnight, and any international pilot knows that Edinburgh is one of the most dangerous places in the world to push-to-test when it comes to this stuff. I hope this guy gets the help he needs, but damn - I'm sorry if I'm not *that* sympathetic about it.