Noreen,I do not have anti Irish prejudices,I have Irish ancestors and am proud of it.
Perhaps I should have said "many of" instead of "the" Irish in the first sentence.
The remainder of my post consists of suggestions as to why so many people, Irish and otherwise, have the belief that so many songs and tunes
are of Irish origen when they are not.
Your second post supports those who suggest the idea that, if it is sung by an Irish singer the implication it is Irish or has Irish connections, leads to so many people of all nationalities believing it actually is Irish.
The answer to the original question "sez who", many ill informed people.
"and why" they can't be bothered to find the real answer.