I have no desire to openly proclaim my patriotism, for the same reason that I have no desire to pray in public: both of them are public performances, more sanctimonious than sincere. They tend to go hand in hand with hypocrisy -- either because such public performance tends to attract hypocrites, or because the people who do such things think that public piety constitutes the full measure of their good deeds for the day, and now that they've earned enough Good Boy Points, they're free to go and sin.
Patriotism is the last refuge of a scoundrel, as Samuel Johnson said, and public prayer is the last refuge of a hypocrite. In both cases people are wrapping themselves in a gaudy cloak of piety to conceal wicked ways.