I think the essence of much of this thread is that of "trust" or (sadly) perhaps lack of it.
In the "olden days" aircraft commanders were much revered people and their word was final. Much of that has changed due to pressures such as the media headlines ("Drunk Pilot Pulled Over etc...), the fact that air travel has become "routine" and that, well its all automatic now anyway, isnt it, - all those pilots do is push a few buttons and command salaries of at least £100,000 per annum etc.
We all know that 99% of aircrew go about their tasks in a highly responsible manner and would never mix alcohol with going on a flying duty.
It seems that our legislators and politicians do not feel it is necessary to consult with pilots, witness the 20 mg limit and also "harmonisation" of FTL across Europe.
I have said it before but will say it again - the ONLY people who understand the pilots job are pilots!! We must spend much more time educating the politicians but I suspect this will be a lengthy process since a major hallmark of the current UK government is not to listen to the people over which it governs.