I disagree. TFA is explaining the mental model Git uses to structure their codebase. If you're writing code for Git, this is obviously very useful to understand, but if you're just using it, this is only one of several mental models available to you. In this case, I think it's right to say that the distinction the author is attempting to draw is immaterial to those not working on the Git codebase.
Yes! It just seems so strange not to care about how things actually are in software. Is it a way of coping with the fact that so much software is so deeply layered and complex now?
Maybe I’m misremembering, but I feel like I didn’t see this usage of “mental model” much until fairly recently. The first I recall being surprised at was a discussion of a “mental model of Javascript” -- why would you need a mental model of something with a very detailed spec and multiple compatible implementations to study? If you want to understand how some aspect works, just look up how it actually does work.
Well, sometimes the API of a piece of software presents one model, while the implementation actually uses a different model underneath for various reasons.
In particular in Git, some commands expose the commits-as-diffs model (cherry-pick, rebase) while others present the commits-as-snapshots model (checkout). However, if you were to look at various layers of git code, the model is either commits-as-snapshots, or neither (compressed storage).
You could also theoretically change the entire implementation of git to store commits as diffs, and offer the exact same API as it does today (probably with differences in the way conflicts are resolved, and definitely with differences in performance).
It's necessary to approximate, but if someone tells you your approximation is wrong it makes no sense to say it's right because you prefer it that way.
If your mental model is that floats are real numbers and someone tells you they aren't, you don't go "I philosophically prefer to think they're reals, so you're wrong". You either update your mental model or decide you'd rather be a bit wrong than learn something (you perceive as) tedious.
