Basically, I think you're reading into it too much. I don't think the OP implied what you think he or she did.
>> I have noticed that, as I get older, I need to hydrate more and more to avoid a headache afterward. Annoying.
Drinking water only helps relieve one of the causes of a hangover (dehydration). There are many many others, so it may not be the amount of water you need to change, but your choice of drinks (clear, distilled beverages generally contain less congeners, which are one of the main causes of hangovers).
As for the parent's suggestion or lack of suggestion of his way being "better"... sure, perhaps I'm reading too much into it, but whenever I hear a comment like that in person, it is, without fail, accompanied by a condescending tone. But I suppose it's a bit unfair of me to assume that's the case here as well, given that I don't know the guy and text is terrible at conveying tone.
However, given that you point out that Europeans of all stripes do occasionally get really drunk, that leads me further to believe that when someone mentions drinking as "a typical southern European", it's hard for me to avoid reading some implication that that way is somehow better.
Drinking water only helps relieve one of the causes of a hangover (dehydration).
Sure. That just tends to be the main, and usually only, cause that really affects me, it turns out. I can predict with near 100% accuracy the presence or absence of a hangover (in me) by how much water I've had to drink. I guess the other factors don't affect me quite as much, but everyone's mileage of course varies.
So it's not unusual for me to go out with some friends, have 5-7 drinks, and not "get drunk", only developing a slight buzz at most. As long as I'm matching each alcoholic drink with 1-1.5 glasses of water, I feel perfectly normal the next day. (I have noticed that, as I get older, I need to hydrate more and more to avoid a headache afterward. Annoying.)
On other occasions, I do enjoy drinking to a point where I'd consider myself very drunk. It's fun. Frankly, I'm mildly annoyed at the suggestion that the European method of drinking is somehow superior. It's just different. Possibly healthier, possibly safer, but I'll be damned if I let other people tell me how to enjoy myself[1].
I'm slightly tempted to write a follow-up article with, "why I don't participate in bro culture", based on this article's pervasive reference to clubs, "certain intoxicants", and other such questionable things the author appears to indulge in, but which seem stupid and harmful to me.
So wait, indulging in intoxicants other than alcohol makes you a "bro"? Damn, dude, check your holier-than-thou perceptions at the door and let people do their thing. I don't personally do any of the harder stuff, but I'm not going to condemn others if that makes them happy. I think you also have a very narrow-minded view as to what a "club" is and what types of people tend to frequent them (hint: the answer is "all different kinds").
[1] As long as my enjoyment isn't harming anyone else, anyway.