This is why I love the idea of mission based gameplay. Kinda like how Goldeneye was back in the day, but with a hypothetical 'save and quit' option (ala Rogue or FTL) so you're not dedicating your whole bloody day to the thing. That way, with save scumming out, game balancing is so much easier for the developer, and difficulty settings can actually have some meaning again.
The reason people save scum is much the same reason Nintendo has raised a generation of people straddling a serious OCD problem. Shitty, poorly designed games have made us fearful. Feaful of getting shafted at the end of a 40 hour experience. Its quite terrifying when you realise just how many weird gaming behaviors are based on fear. Smashing up someones house like a psychotic blind cat? Well, perhaps that one-off key-in-an-inconspicuous-jar that you missed back in A Link to the Past has made you fearful of leaving any stone unturned. Saving before and after every single event in-game whilst turning half your harddrive into some sort of perverse archive of savestates, shivering like a madman? Did you miss a limited time achievement in something of late? Or maybe the uber sword of alternate endings back in an old SNES title.
Metagame fear does not belong in an activity performed for fun.
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Pretty much once a game hits the 5 hour mark of total gamplay length, from start to finish, developers need to make a choice to satisfy gamers, and perhaps even write this up as a promise to the user in the manual or something. Namely that the game is either:
a) Impossible to cock up. Like Metroid. Or Kirby. Or Zelda. But not Zelda 2 or that Minish Cap with the buggy light arrows you can miss just before the end (restart time!)
b) Level based, or unlockable roguelike based. Goldeneye and The Binding of Isaac are my two examples here. Each level/run is self-contained, but the unlockables list is designed in such a manner that any action you perform can't cock up your save state. Just please include a 'save and quit' feature. Oh, and returning to Zelda for a sec, Majora's Mask as an exception fits here too.
c) Open world, sprawling and character centric. Nothing short of Morrowind in scope so your cock ups don't just not matter: they are the game. I picked Morrowind as the example because that game even stuck in an entire second main questline for psychopathic murderers (kill Vivec and follow the hints to the Corpreuseum to trigger it).
Anything short of these three outcomes I feel is poor game design. Fine, and even encouraged, as part of an optional mode (ie: Hardcore mode), but not in the vanilla game.