What's right or wrong about "heavy drinking"?

I would point out that we have the same thing here, with vaguely credible government health organisations prescribing bizarre limits based on paltry or no evidence. Fact is: we can tolerate more alcohol than is usually prescribed, and its effects on the human body vary from person to person and on the kind of drink being consumed and the circumstances under which it is drunk.

As such, I think what Diana said there is quite right: the matter is one of principles, not of directly prescribing what you should do to effect the right level of drinking, but instead pointing out when drinking may be a problem - i.e. when you are regularly drinking into a stupor instead of doing something else to have fun. It is a very easy way to while away the evening, to kick back alone with a six pack, or a bottle of whiskey, but it's not exactly achieving your maximum potential if that's your general way of enjoying the evening. As Diana rightly points out: she isn't arguing for some puritanical rejection of fun, but just pointing out that such a mode of enjoyment is simply not as good as the many other things one could be engaged in (indeed, it's not really "enjoyment" as much as it is a release from a pressure to enjoy oneself).