I think that this may go deeper than we think, while I certainly like the idea of winging it in a public bar, ( I may Try it!) I doubt that this will be the full answer. It is a bit like a question I often ponder: If you are an Irish/Scottish/Welsh/Cornish Nationalist, that's fine; If you are an English Nationalist, you are a Facist.
Perhaps people are worried to dress/act/sing in the traditional English ways, or take part in anything 'ENGLISH' for fear of upsetting Hook the Moslim Cleric or other minorities. The number of councils who BAN the flying of The Cross of St George, even on the saint's own day, grows by the year, one of the main resons given for this, is that it may cause offence to said minorities; Christ! can you imagine the hoo-ha if we actually celebrated being English by SINGING about it!?
Your thought & responses to these thoughts most welcome.