Why are honor limits a thing?

I never knew honor limits were a thing until today. I've only been playing for a couple of months now, and no one ever brought this up. Why is there even a limit when the majority of players don't honor each other? Instead this meant that I could not honor all the friendly players I ran into today.

Yes, I know it's not that big a deal but I just want to know why there are limits to how much honor people have.