Earlier quoted context omitted.
Entrances != Egresses. Do you ever notice those doors that say emergency exit only?
Which history shows us tend to be locked or barricaded when they're not supposed to be, or obstructed in some other way, or otherwise unavailable. Sure, there are other egresses available in principle. Hell, you can sledge-hammer your way through a wall in a pinch. But in any practical sense? Having two primary ingress/egress points is a horrible idea.
I know that its hard to to believe that there has been progress in the last 100 years, as we sit here communicating effortlessly across the globe, protected from huge numbers of diseases that ravaged humankind, enjoying workplace fatality rates decreased by multiple orders of magnitude, enjoying universal suffrage, etc etc.