A 14 day quarantine isn't a lockdown, even NZ is getting sloppy with virus measures. If the people there get tired of it there is nothing the government can do to stop them. In China you will get quarantined forcefully by the police state, and if you don't like it you can go to prison or get disappeared if you raise to big of a commotion.

New Zealand has cases, so what exactly is your point? The initial argument is that locking borders could prevent the spread of a highly contagious virus into a country. It cannot.