We’re not much interested in indoctrination here. And clearly a mandatory pledge of allegiance is meant to indoctrinate. But even where love of country is strong, we recognize caveats that might make people uncomfortable to pledge. Religious or moral beliefs that supercede loyalty to a government. A belief in civil disobedience. Discomfort with the very idea of unquestioning loyalty. Or the recognition that in a free country, maybe we shouldn’t be swearing fealty, and our refusal to speak the Pledge comes from that love of a free country.
There is a difference between patriotism and a rote oath. Either you love the country or you don’t. But any patriotism will be strongest when it comes freely.