It's because folks are simply out of the habit of listening. I have no trouble with accents, Irish, English, Scots, Australian, deep south, bring them on.
Because it is such long time since they left the Ireland.
because English is their second language
Americans have a hard time understanding Australians too but more because they think we speak to quickly
We like your Irish soap but you guys kinda talk funny you know what I mean. hehehehehe hop-hop.
I fully understand it, but I also very much like Irish people, being of Irish decent myself
Americans are not good at understanding accents because they aren't exposed to them.
If you were exposed to many people with Irish accents, you would understand them easily.
I think the problem might be the Irish with this one.