The logic is as follows: I need to be up early, my parents always get up early, and my alarm almost always works. If I have both to wake me up, there's a good chance I won't accidentally sleep in.
As long as it's a rare occurrence, I don't really see the problem here.
https://www.psychologytoday.com/us/blog/feeling-our-way/2014...
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.
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?
I recently decided to wake up earlier (have kids, wanted an hour or so to myself before they woke up), so I started going to get earlier. Instead of an alarm in the morning, I have an alarm at night so I remember to go to bed on time.
For something as important as a final, you should be getting a full night's rest. It's just not worth whatever little you can cram in the night before.
The only time I asked someone to wake me up was for an early morning (started at 7 or something) class I took with my roommate. We went together, so we agreed that we'd both make sure the other was up. After that semester, I never signed up for an early morning class again (but I did okay in the class though!).