I Ford it has everything to do with safety.
A few years ago during one of the xmas drink drive campaigns they showed a presenter on the local news here driving a car simulator. First, with no drink at all..then with progressivly more. The results? From the first drink thier ability to drive was impaired.
I stopped a woman driving out of Heathrow one evening. Her driving was appauling. She got out of the car, appeared stone cold sober, she probably was 'sober' in that she wasn't drunk. She gave no real indication of having been drinking at all...Having established, as far as I could there was no other reason for her bad driving, I breath tested her. Result? She was double the drink drive limits.
Now, these 2 examples are obviously car drivers. However I would suggest to you that the level of impairment you can get away with in a car is higher than it is in an aircraft. Secondly, there are many references to fatigue on here, combine that with alcohol and the problem is exassabated.
Turning to your suggestion that about drunkenness. NO ONE HAS SUGGESTED THEY WERE 'Drunk'.
The offence they were both convicted of has to do with an arbatary blood alcohol limit, not a level of drunkness or otherwise.
A 'Sobriaty' test is irrelevent.
Remote, and others who suggest starting a war with security staff, a word of caution. Think about it a while. Security are not subject to the same legislation, rightly or wrongly. You can accuse them, and one or two may be sacked. What effect do you think that will have in return? It's been suggested that the security staff 'should' have had a word with the captain, do you think a security guard is going to be more disposed to do that if he read this and the related thread?