I've only discovered in the last few years that my great grandfather fought in the first world war. I'm an Irish nationalist raised not too far from where James McClean grew up and only found out about the fact when my uncle died and my great gandfather's medals passed on to my Dad. My father had always known but in Irish catholic families in the north of Ireland it was like a dirty little secret that was never talked about. In recent years though my Dad started getting really interested and researched the history and even travelled over to Amiens to see where his grandfather had died. Turns out he had first served in the Second Boer war and then did 2 tours during the First World war.
Now here's the dicotomy, the same uncle who passed on those medals to my own father had also been interned without trial by the British Army in the 1970s simply because he was an Irish nationalist. My father himself attended many civil rights marches in and around Derry during the 60s and 70s including the march that preceded the bloody sunday massacre. He had to identify the bodies of friends shot dead by british army soldiers and in doing so was threatened by those same soldiers. Although he has never talked to me about it and I have never been able to ask him, I know from my Mum that he was abducted, beaten and held for 3 days by the british army on the very day they brought their first child, my sister, home from hospital. Despite all he witnessed and experienced, he doesn't hate Britian or the British. He has loved United since the 60s, worked in England for varous periods in his life when work was scarce at home. He would never wear a poppy for much the same reasons as James McClean has outlined, nor would I for that matter and anyone who would take issue with his reasons for that are clearly blinded by jingoism.