How exactly is this different to, say, maths, where there is an assumed precedence and when you need to either make that clear or change the order you use parentheses to encapsulate the inner calculation?

What it sounds like is that the Unix shell syntax was established how it was, everyone built on it with all of its syntactical conveniences, and suddenly there's 100% buy-in to the idea that a computer just can't handle a filename with spaces in a shell.

    ./cmd do-something-with --force file with spaces


    ./cmd do-something-with --force 'file with spaces'

That's one of the main problems solved. If you're expecting to run an executable with spaces in it, like this:

    ./do something with cmd --force 'file with spaces'

Then it's another problem but one that can be solved by convention. A GUI can happily execute `./do\ something\ else` but if you're in the shell you've got completions, aliases, functions, symbolic links...

And if that's not ideal, then `./'do something with' cmd …` should be good enough right?