This is probably the best game to test this approach on.
Background: Resident Evil (RE) has had a Mercenaries mode in RE 3, 4 and 5. It is a mini-game where you have a timer counting down in each level. You kill enemies, rack up multipliers that fade quickly unless you continue your killing spree, and you can get time-extending power-ups. In short, each level is at most 10 minutes, usually no more than 5 minutes. There were unlockables in RE 3 that went back to the main game. In RE 4, you unlocked other characters (and levels?) and if you mastered it, you get the 'hand cannon' magnum that can kill anything with one shot.
Mercenaries is a highly repetitive Resident Evil mini-game. RE: Mercenaries 3D is that very same game play over and over again. What do you unlock? Additional characters? High scores? Pragmatically, there isn't much *worth* resetting the game for, except to unlock characters or costumes all over again. Plus it is on the 3DS, which means a lot of kids playing it; when I was a kid, I would have thought that getting the game already with all the unlockables was awesome.
While I am personally irritated that you cannot wipe the game's save, I do understand that this is the best type of game to try this BS behavior with, because there is very little to actually reset.
Ultimately, it's like not being able to reset that Mortal Kombat 3 arcade machine that someone already unlocked the hidden character, Smoke, on.