You can walk across it. Took me way too long to do so. Even up close it’s an aesthetic and engineering treat.
https://www.goldengate.org/bridge/visiting-the-bridge/bikes-...
Wonder how long before they try to use ML instead of the human judgment..
But I suspect you’re also right they don’t want pedestrians at night due to the suicide risk.
I once had my derailleur break at night while crossing the bridge and had to walk. They sent out a truck pretty quick to check on me.