This is yet another case of complex problems having solutions that are simple, straightforward ... and wrong. As the Irish Times article documented, the new law seems to have done little to abate the problems it claimed to address and created a new raft of problems in its wake.
There's a part of me that gets a little socially Darwinian about this sort of thing. A certain proportion of people have always had issues with self-control, aggressiveness, and delusions of invulnerability as they pass through their late teens and twenties, and alcohol consumption seems to heighten these effects. No laws or rules have ever been able to, nor, I believe, will any bright new ideas be able to put a truly significant dent into this problem. The best we can do is try to limit the collateral damage to themselves and others.
There are points of diminishing returns where overly restrictive laws and taxes no longer address the problem and simply provide the black market with the opportunity to charge outrageous prices to provide cheap services simply because fairly innocuous behaviours are prohibited or taxed to annihilation. The lessons learned by the US in the wake of the prohibition era are being perpetually forgotten and re-learned here as well as in other jurisdictions.