> Normally with that kind of GDP you'd also have a solid tax base to go with it, here it is the opposite

You are badly misinformed. The Irish state is actually in receipt of colossal quantities of corporate tax each year, which has placed it in a significantly stronger fiscal position than most other EU nations.

Whether this state of affairs is sustainable in the longer term is another question, but for the last ten years or so, the strategy of encouraging FDI has unquestionably paid off extremely well.