If you don't like what the law says, work to get it changed.
I agree that teaching children about alcohol use is important. The laws in your area may be different than those where I live, which may account for some of the disagreement going on. Here a parent can, within certain limitations, provide alcohol to their child. Here there is no restriction on providing alcohol to minors as a part of a religious ceremony. I have absolutely no problem with the fact that the laws here allow parental discretion regarding their own children and the use of alcohol and balance well with other laws that might be applied, such as the child abuse laws. Wine during Mass or Passover Seder (even the Shabbot meal) is vastly different than hosting a keg party for your teen's entire graduating class - unless you are like the one group of parents I am aware of who were all in attendance in order to meet the law's requirements that only the parent of the minor can serve them alcohol.
Underage drinking usually (but not always, I readily admit) leads to intoxication. Underage intoxication usually (but not always, I readily admit) leads to personal injury, property damage, and/or utilization of criminal justice assets (cops, courts, jails/detention centers). I'd rather bitch about cops and judges not dealing with real crimes and real criminals than have to bitch about the underage drinkers who are causing me to pay taxes to support infrastructure devoted to the consequences of their behavior. The costs of cleaning up the vomit and disposing of lost articles of clothing left behind by many underage drinkers must be covered somehow. Insurance companies are not, to my knowledge, in the business of paying out on claims for damaged property or personal injuries without attempting to recover those expenses. This is all most often accomplished by passing the increased costs along to the other consumers - of which I am one.
Turning back to the original issue - the series of articles - I am still confused about the motivation for exploring the matter let alone publishing the articles. The problem exists and everyone seems to be aware of it. The problem exists and a significant proportion of the population does not seem to care that it exists - even to the point of working to make it go away by revising the laws. There is nothing new or unusual about the violations of underage drinking laws, just as there is nothing new or unusual about a significant proportion of the population not caring that those violations are taking place. I am disappointed to learn that a community of supposedly conservative (as opposed to hippy/commie liberal) and libertarians seems to be saying that there is "no harm/no foul" in underage drinking as that is generally encountered in our society. It's not so much hypocrisy as it is contradictory. Or is it that my disappointment was confused for something more akin to absolute adherence to the letter of the law in spite of the moral flaws in the law?
stay safe.