> How is "reflog" the correct and intuitive choice for "undo"? Was there something I wasn't understanding? No, I'm just supposed to accept that.

Actually your initial intuition was correct. There are things you obviously don't understand about git. "reflog" is short for reference log. As "git help reflog" will tell you:

  Reference logs, or "reflogs", record when the tips of branches and other references were updated in the local repository.

It isn't arcane. It's perfectly logical choice for what the "git reflog" comand does, as explained in the man page: "This command manages the information recorded in the reflogs."

Now if you don't know what a reflog is, you will be confused by this. But the solution to that is for you to learn what a reflog is. And yes, in order to use git well you need to have at least a rudimentary understanding of how it works.

I know that some people do find git hard to understand. Often that is because they want it to work a different way than it does. But git is a fairly complex tool designed to solve a very complex problem. It does an outstanding job of doing what it was designed to do. However, if you are not willing to invest the time in understanding git to a minimal level (and many people aren't), you will find it to be confusing.

There is no need for "sanity" to "come to the naming of commands" for git. The commands already have sane names. But if you don't know what those names mean, it will seem to you as if they are in a foreign language. Most of the confusion people have with git is due to them having an insufficient level of knowledge of how it works. Again, if you want to use git well, you have to gain that minimal knowledge . If you are not willing to do that, then you should either become willing or choose to use some other version control program that is more to your liking.