Ireland's economy appears to have been a real rollercoaster.

If this play takes place during the 80's, that may have been a low point.    Irish Independent 24 Oct 2004 (is this the voice of the business community?):    in the 80's Eire was a "land of high tax, high unemployment, high debt, high emigration, one of low growth, little opportunity and less hope". It's no wonder there would have been bitterness.

Then came the period of high foreign investment,   including lots from the US: Dell, Intel and Microsoft all invested heavily.   Partly due to this, employment went up.

Next was the housing bubble (and the banking crisis)--and its bursting, with those consequences, exacerbated by the worldwide recession.   Irish Times   22 Dec 2013:    "By 30 Jan 2009, Ireland's government debt had become the riskiest in the euro zone."

It did not help that it appears that the gap between the highest and lowest income households actually widened during the period of the "Celtic Tiger".

So it's understandable that the bitterness may well be back--though perhaps not directed at Americans, perhaps partly because of the US investment and jobs resulting (and perhaps since US tourists may spend more heavily than others). Also quite a few US tourists--supposedly 40% of the US population traces ancestry to Ireland--feel kinship, justfied or not, with Ireland.