While I'm today really sad because of Jeff's death, I'm also a bit...... well, angry. It was a well-known fact that Jeff liked booze a little too much and his other health problems may have been a final contribution to fatal cirrhosis.
I'd really love if music artists would finally learn from examples like John Bonham, Rev Sullivan, Paul Gray, Jeff Hanneman....... and stop ruining their health with irresponsible, childish drinking/drugging habits. I'm fed up with great musicians passing away in unnecessarily young ages.....
I think the problem is that it's expected of them. Rock and Metal live off the aura of their glory days, and those were the sex, drugs and rock'n roll days. Combine that with a) that a lot of metal bands enter the scene with that attitude, b) they aren't the most cerebral type and c) a lot of classic albums were written under drug influence, and that's how you end up with those situations.
It's interesting. I've been reading Nikki Sixx's Heroin Diaries, and something he kept asking himself was why he couldn't be like the other guys. They all did tons of drugs and alcohol, staggering amounts, in fact, but only one of them had a problem with it. The thing to remember is that some people can deal well with drugs and alcohol, and some people go completely off the rails. While I agree with all of your observations, I'd add that they probably see all of their peers coming out of it alright (hell, if Aeromsith and the Stones are still around. . .), and assume that they're going to come out of it just the same.
I'll also throw out that Niiki Sixx is adamant that he'd have been every bit as big a junky had he not been a rock star. Motley Crue gave him the money to do it well, but if he'd been living under a bridge he'd have been no different. Remember, rock stars come from the same pool that the rest of us do.