[goodcanadian]

Bonus points to people who can give a rational non-imperialist argument as to why Ireland, Cyprus and Malta nationals get that privilege.

Well . . . the reason is pretty much imperialist in nature. In recent history, citizens of those countries (along with citizens of commonwealth countries) were unequivocally citizens of the United Kingdom. When the countries became independent, the UK government chose not to take away those erstwhile citizens' right to vote.