Very good points on evidence-based practice. The aviation industry tends to get very smug about managing to dispense with a culture of blame, with progress on CRM etc., but tends to forget that much of the change over the last thirty years or so has been carried out in spite of the operators, not because of them, and that evidence-based practice is sadly very lacking.
An article in "The Sun" or a "documentary" on Channel 4 by a journalist who doesn't really understand the issues is not evidence, but the politicians tend to act as if they were.
There is also, sadly, a culture of blame within the pilot fraternity when it comes to drink. We see plenty of comments on PPRuNe when a pilot is discovered to be (or accused of being) over the limit along the lines of "Serve him right - his behaviour reflects on us all - throw the book at him - pull his licence - why didn't his F/O shop him..." etc. without people knowing the facts surrounding each case. Such pilots know perfectly well the penalties for drinking. Yet why do they do it? A reaction to stress? Coping with fatigue? Driven to it by political machinations within the company? All sorts of possible factors there. Alcoholism is not a cause of accidents (I would suggest). It is a symptom of other problems which need to be addressed.
I do not suggest that an alcoholic pilot should be permitted to continue flying. But if you penalise him instead of understanding what the problem is, you push others suffering the same problems into hiding it. And a hidden problem cannot be addressed. Problems only become manageable when they are visible.