It sounds like the morality argument is in two parts:

It might not be the best choice to start a conversation with a stranger by complimenting them, but you’re welcome to pick something public and inoffensive like their taste in alcoholic beverages or an interest expressed through clothing (writing on a shirt, a pin or a brand on a bag). Feel free to learn something…

Better move - leave the carrier out regularly, put a bed in it, and periodically drop a couple treats or a little bit of food inside. Make it your cat’s happycozy treat shack, and it won’t be a problem. Also helpful - get a carrier that has a removable roof panel. It’s less scary for the cat and easier to get in…