I'm pretty sure the consensus is that positive reinforcement, when used consistently and over a long time, can be used without any negative reinforcement and still get the requisite training results. That's leaving aside the fact that negative reinforcement is bad for the relationship with your child and/or pet.

Completely on this subject though, I find the behaviour in question here insane. Mostly because adults are supposed to be independent and competent. Of course, not everyone is raised equally. If this works for them, who are we to judge?