The creation of /, iirc, was initially meant strictly as a way of internally enforcing constraints when interfacing with C libraries. It just so happened that someone dug it out and went "what is this?" and then core devs agreed that it should be surfaced and officially supported.

Personally, I find * useful and / fugly - because positional parameters are very opaque when reading code. They also don't give a chance to the IDE to guess what each parameter is meant for.