Surely that's quite an important point. Banning guns would reduce the number of people killed with guns. Restricting pub opening ours (as used to be the case) presumably wouldn't stop people getting drunk and behaving badly. And restricting how much people can be served would be tricky to police.
He didn't ask where he was born, or say 'what dumb race behave like that', or similar, he asked what dumb nation gives people all that shit. It was the US that gave him all that shit, not Britain.