The Irish thing, frankly, is because the Irish are big on themselves here in America; look at movies over the decades, and songs, and documentaries (as if only the Irish came here; but 2nd would be Italians and 3rd Jews as far as hype). Come on; turning St. Patrick’s Day into “Irish Day”, while no other nationality has such a “Day”.
(Waiting for the flame-throwing to start.)
Speaking as a native New Yorker, I second your thoughts. Don't get me started on the "we were treated worse than the blacks and Injuns" BS. The truth is, the Irish were running most of the large cities from Boston to Butte 30 years after the famine, and were at the forefront of the movement to ban Asians, southern, and Eastern Europeans from immigrating here.