Why two throttle cables?

[Gene]

I remember when every (Japanese) bike I was familiar with had one throttle cable, of course to pull.

Now it seems that all have a push/pull throttle cable. Why? My first thought was in case the slide/butterfly got stuck, basically for emergencies. In all the riding I've done in the past with the single cable, never had that happen, but of course it could have happened.
I have a 1991 Toyota pickup, it also has the dual cables. Now I'm confused. I can't see the throttle being stuck on my pickup, and me leaning way down to try to pull the throttle back closed. Maybe I could try with my foot?
Anyone know why dual cables? There must be a good reason.

[mollusc]

I believe it's mandated by law on bikes.  Not sure about other vehicles.
Each one pulls in a different direction.  That is, closing the throttle isn't just relying on a spring to do the work.  When you're rolling your wrist, the second cable is pulling the throttle closed.