lordsummerisle makes a very relevant point in that it is surely a question of education and information? Some do not seem to be aware of the length of time required for alcohol to dissipate from one's system.
During an enforced sabbatical from flying I worked as a Railway Signaller for nearly three years. I must pay tribute to my employers (Network Rail) who briefed us comprehensively on the effects of alcohol (and drugs) and also the company's policy in this respect. The information that lordsummerisle lists was covered in great detail and was also updated on a regular basis. As an employee I knew exactly what the rules were and why they were in force. I could be randomly checked at any time and in the event of an incident/accident all relevant personnel would be screened. I am not suggesting that random testing is required in professional aviation (an arguement which has been covered in other threads before).
Finally perhaps one of the myths which we need to overcome is that imbibing of alcohol makes you sleep better - without going into the details, it does NOT. Your quality and length of sleep will be worse after drinking alcohol and, indeed, it may takes a few sleep cycles to get back to "normal" after a skinful!