The reasoning that Ireland's tax policy is theft is not discussed here from a "taxation is theft" perspective, but from a "we should tax the rich" perspective. Because Ireland is in the EU, this effectively halves taxes on most big international companies in the EU (less than half of what it is for everybody else/normal companies in the EU), and makes it 12.5% for a few specific FANG companies.

Which is deeply unfair, from two main perspectives:

1) everyone should be taxed the same. Big, small, local, global, ... it should not matter (if anything global should be taxed more than local)

2) it only works because everyone's tax revenues go down a lot, which means yet again the rich escape taxes

3) it makes something like EU corporate tax initiative, which is horrible (it involves an extremely complicated way of attributing specific transactions to specific locations and then taxing them locally. However, like the EU VAT initiative it's main problem is how complicated it is)