This is rewarding bad behavior. The offspring should be conditioned to awaken themselves by having an unpleasant experience occur when they don't awaken when expected.
Nobody wants to avoid the behavior when punishment is introduced, they want to avoid the punishment itself. Typically speaking, this is done by circumventing the punishment, rather than correcting the behavior. Besides, (almost) nobody purposely sleeps through their final - especially not if they take the time to ask someone to be a backup alarm. You'd be advocating for punishment of an accident at that point, which is aggressively useless at best, and sadistic at worst.
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?
As long as it's a rare occurrence, I don't really see the problem here.