I am totally that guy who saves his RPGs regularly so I can go back and explore a different choice. I kept my thumb in the page of choose your own adventures too. I'm a completest, and I hate the idea that maybe I missed some interesting branch or event because of a bad choice early on, so I take steps to protect myself against it. I don't think this is uncommon, though obviously it is a matter of degree.
Computer Games seem to be built on the same assumptions I'm making. Some of this is a function of the medium - if you can save and try something else, why wouldn't you? - but some of it is also habit. We understand completion. Computers and computer interfaces are really good at expressing ideas like percentage complete, but more nuanced ideas can be harder to express within the medium. Most and least are easy, but fuzzy numbers are hard. Plus, for programmers, it's stupid to build content to NOT use. Writing a game which a player will only experience a fraction of might be a great idea, but it's a rough allocation of resources.
This point came to mind while listening to the excellent Walking Eye podcast featuring Ryan Macklin, John Wick and Eddy Webb. Unsurprisingly, it's an great listen, but there's a brief moment of talking about engagement in video games that left me chewing on my own experience and considering that the prices of a compelling narrative in play may be paid out of traditional gameplay rewards, and that price might be too high.
One of the hardest lessons in life is that everything you do is ten thousand things you don't. This is an important thing to learn to understand yourself, and it's also something important to understanding drama. A story that could only have ever gone one way is a poor start as a story, and dead weight as a game. Sure, you can get some mileage out of illusionary choices, or choices that exist solely within tight boundaries, but we've already milked those about as far as we can. If you accept that deeper, more personal drama in video games is a desirable outcome, then I suggest something more drastic is in order.
What is that something? If I had a whole answer to that, I'd be off in Austin making big bucks. But I have bits of it, and the bits I'm really staring down the barrel of is this: Meaningful choices demand that the paths not taken be rich, and doing that well demands a patience for waste and frustration which, I think, is far riskier than most game designers can afford.