Isn't it even more than that, that a large chunk of the people who don't want to get vaccinated legitimately don't care if they never go overseas?
The correct policy is: Screw them. I am entitled to leave. They can be vaccinated or not.
Spot on, plus I think there is a benefit from having a date for the borders open as a threat to the unvaccinated; with the prospect of a surge in cases from inbound travellers, they’ll head out and get vaccinated