I flew KLM to JFK a few years back. My lasting recollection was that they only served us 2 alcoholic drinks during the entire Atlantic crossing, including those served with the meal. OK - so I was travelling with my ice hockey team and perhaps they thought we might get a bit loud, but those not part of the main group were also limited to a couple of bevvies.
Yes, we all know about the legal requirements not to be drunk on a plane etc, but the way in which it was forced upon us wasn't appreciated. Granted, it's difficult to determine when one person is drunk and another isn't, so I guess a predetermined limit as to the number of drinks which can be served needs to be set and will not please all of the people all of the time....