I'm guessing parent, like many here on HN, tend to travel internationally at least once in their lifetime. And then a passport is "forced" upon you, if you'd like to transport yourself across international borders (unless Schengen or similar areas).
In that case it’s simply a question of what you value most, your biometric privacy or the ability to have an international travel permit. It’s a choice; neither option is forced on anyone.
But no one chose to be presented with that choice. Ideally we would be able to have both biometric privacy and international travel.
Well, to be fair, a lot of people probably do support the idea that their own country checks the documents of people who enter and exit through their borders, and are maybe glad that the country they are visiting is similarly careful, but in principle, someone might want to emigrate to Antarctica, and never return to their country of birth, and for them it would be an unnecessary burden to have to apply for a passport.
Which really entrenches a specific philosophy of what the relationship should be between the state and the citizen.
A mandatory ID card says that every citizen has to prove their validity to the state, and it is the state which can grant or revoke that validity, rather than the state being the servant of the citizens.
There have surely been enough examples by now of successful countries not requiring mandatory ID cards, and examples of ID cards being abused by governments for discriminatory policies, that I don't know why they have such support.
