So, if you are living in London and not paying taxes(to Ireland), you are not Irish? Dude, you are clearly mixing ethnicity and nationality. Plenty of Irish in UK, that does not know Gaelic - same situation in Ireland. There are in fact more Irish Gaelic speakers living in USA/Canada than in Ireland.

And Americans are claiming ethnic ancestry - not national ancestry. And many Irish migrated out of Ireland, when it was not a country - and paying taxes is irrelevant in this gatekeeping of identities.