"Play the ball, not the man" !
No, play the man. The ball doesn't fly the aircraft...
A lot of what you say is true, Capt Playstation, however the bottom line is that you can't have "drinking men" flying aircraft while under the influence... and lifestyle is a poor excuse for such behaviour - pilots know what is expected of them, it is drummed into them by regulation and company policy. Everyone knows the rules; only the truly foolish (or utterly helpless) risk their careers to feed their addiction. The world changed when those BA pilots got caught flying shortly after being filmed drinking.
If you can't exercise the required level of self-control, you should choose a different career (I suggest medicine, they all drink like fishes).
And yes, I too have sent a few people home when they showed up for work rather the worse for wear...