This reminds of a comment, where someone never having used a typewriter before, commented that people in the olden days were prescient enough to put #(hashtag) on the keyboard, before Twitter was invented.

Or someone finding a floppy disk and saying – oh, that's cute, a 3D-printed Save icon!

it's not the name it's how and why it was on a tape

> how and why it was on a tape

I think you're overthinking the whole thing, it's not really "on" a tape. It's the default operation of a tape, they didn't have to come up with the idea, it's a side effect of the medium. You need a motor to move the tape, no motor = no movement = the tape stays in its current position. To automatically rewind the tape you'd need some sort of mechanism under tension in it which would probably make it less reliable / more expensive.

Indeed. A cassette was a miniaturization and interface improvement over reel to reel systems. So it inherited some of their properties but added new ones (like the protective case) and lost some properties (like splicing or adding and subtracting length of the medium)

You can splice a cassette but it's relatively inconvenient. Adding time to the medium is limited by the capacity of the case.

What I really want to know is whether the fact that a standard pencil could be used to manually wind a cassette was an intended feature or a happy accident.

I would wager it was the latter as Philips missed a trick in rebranding it as an accessory/dongle and monetising it. Now, if it was Apple..

I think it is intended.

And there is an equal number of times where this ‘feature’ is(was) annoying. I.e rentable video tapes returns

Motor or Bic biro. Essential for those times the car player (it was always the car player) mangled or despooled half the tape.

that's what I was hinting at. Did the designer really think about it or was it just naturally there.

They didn't think about it.