Sending one Nxt to accounts with bad passphrases wouldn't do anything. It wouldn't lock the accounts or prevent people from using them. On the contrary, it would probably encourage individuals to use those accounts with bad passphrases because they would get one free Nxt.
Yeah, that's a wrong way to do it.
The right way is to explain to people what a really good passphrase should be.
Or generate it randomly for them.