It seems that this thread is degenerating, as with many other previous threads, into a squabble over which is the more serious problem, drunkenness or fatigue.
That is really regrettable because it is patently obvious that both problems need to be addressed and this type of argument effectively tries to reduce the significance of each in order to accentuate the significance of the other --- that is a lose / lose.
I don't see too many real opponents to the argument that duty cycles and resulting fatigue are perceived as a serious problem by pilots. This will only ever be resolved by getting airline management to see and acknowledge the problem. How can you do that? Whatever the answer, please don't denigrate the arguments to limit and control pilot inebriation as an means to highlight the fatigue problem.
While the use of drugs and alcohol may be a much smaller problem from a safety perspective, from the perspective of the paying passengers, it is not.
When the newspapers print a report that 40% of pilots confirm feeling fatigued while in control of an aircraft, the average oik won't even read past the first few lines.
But when the same newspaper reports a drunken pilot collapsed in his seat they will read every line and it will quite probably come up in conversation with their friends later, in the pub.
Whenever it happens it IS a problem. And it happens all too often
The problem is not simply that the pilot was incapacitated, but that he got as far as through into the public eye before being intercepted.
Existing self-policing policies may be quite adequate to ensure that incapacitated pilots do not actually get into the air, but they are clearly failing to assure the flying public that this system is effective.
Any argument that pre-flight screening in the crew room, or wherever, out of the public eye does not guarantee 100% interception of incapacity is a weak argument.
But then, nothing in life is 100% guaranteed.
Such a system can be implemented and eventually will be, despite all protestation, not because it will be 100% effective but because it is more effective than the current honesty-box system and because the paying passengers will come to expect it.
Hell, 12 or 18 hours from bottle to throttle; what does that really mean?
I have seen drinkers who have been drinking heavily (not necessarily heavy drinkers) who could not be safely trusted with a can opener 40 hours after their last drink. Let them in to control a passenger aircraft? Not one that I'm sitting on, thank you.