All spiral staircases have a single guardrail. That’s why they aren’t double helix staircases.
It’s not weird at all, it’s quite sensible. The purpose of language between people is not to produce correct sounds, it’s to facilitate some other activity or intent, so people will tend towards whatever manner of language makes achieving their goals the easiest.
It’s the same reason desire paths form: it’s less effort.
It also looks like a spiral when looking up or down.
A guardrail isn't a safety barrier? The photos of the staircase don't look like star wars walkways to me at all.