Dan D'Air - don't despair.
It's clearly an education problem and I agree with Pr00ne it would be interesting to understand this individual's particular misconception(s) about the meaning of the poppy and try to counter them.
If he understood the history - going back to WW1 and really understood the sacrifices which have been made by people from throughout the commonwealth, perhaps he would feel differently. I have spent some time in the vicinity of Monte Cassino and, in addition to the over a thousand Poles buried there, the commonwealth war cemetery contains British, Kiwi, Gurkha and Indian troops and of course this is just one example of many.