The philosophical argument here is "To what extent is it the government's job to regulate substances?" The author seems to think that if it causes harm, it should be under the government's purview to curtail. The second-to-last paragraph demonstrates this position. We already have laws about driving while intoxicated and public drunkenness (among others such as carrying a firearm while intoxicated) which preserve ind…
It's not a 'philosophical argument' - it's a very practical argument.
Alcohol is regulated pretty much everywhere, even where ages are lower, there is definitely a social contract around it.
Young Germans don't just go around getting wasted at 16 'because they can' - there are still social norms, in addition to real laws.
I interpret a lot of discussion around here to be very academic, more contemplative of issues such as liberty, freedom of expression etc. - but my own personal experience relating to this is more applied: I've heard numerous stories about my family members way back a couple of generations and how alcohol was fairly intertwined in all of this. My family was relatively average. These things can be a huge social malaise.
For example 'heavy/problem drinkers' account for most alcohol sales. [1]
Basically, the alcohol industry might not exist without alcoholics.
The top 10% of drinkers average 80 (!!!) drinks a week [2]. On average. That's just a crazy amount of alcohol for an average, and that's the top 10%, not the top 1%.
The problem is similar to that of other drugs: for most people it's probably not going to be a problem, but for enough of society, it will be a problem to the point wherein it affects the community ... ergo ... regulation and social norms of some kind are unavoidable.
"The author's suggestion that we once again need to start molding what is "acceptable" leisure is simply backwards. Western liberalism is fairly good at solving these problems."
100% of 'Liberal Western Democracies' regulate alcohol in a meaningful way.
Even in Germany: "Selling or serving spirits or food products, containing more than insignificant quantities of spirits, to a young person over the age of 14 but under the age of 18 years" - 2000 Euro fine for retailers. [3]
The author provides a different angle on prohibition and I think the very vague conclusions of 'finding middle ground' are reasonable.
[1] https://www.theguardian.com/society/2016/jan/22/problem-drin...
[2] https://www.washingtonpost.com/news/wonk/wp/2014/09/25/think...