Kilbane is an Irish citizen since birth and both his parents are Irish. It would be news to them to claim "Ireland had no input" into producing him. Sheedy was born in Wales but has also been an Irish citizen since birth as his father is from County Clare. Carsley has a more distant relationship with Ireland - his grandmother was from County Cork.
Emigration since the famine has coloured our concept of Irishness. I'm no nationalist - these players may all very well claim Englishness as a central part of their identity too. But Ireland very much had a role in the stories of these people and their people.
I wouldn't be "thanking" Ireland, either. It's an accident of birth where one is born - or where one's ancestors were born. But these players can claim as much or as less Irishness as they like as far as I - an Irishman - am concerned. Their Irishness was coloured by the journey of their parents and grandparents. Mine stayed in Ireland. That's the only difference. I live in Germany now and my son is half-German. He's every bit as "Irish" as I am. Heck, he identifies with Ireland more than I do.
All that said, Seamus has been a great servant to club and country - but time for him to move on from both. I admire his determination to play on - but the club and his national team need to ensure their standards are high enough such that players nearing retirement realise that they are no longer good enough to get a game. Seamus, clearly, doesn't feel that yet. That's not a criticism of him - but of Everton and Ireland.