What's the point of pointless math?

A math group that I read recently mentioned a branch of mathematics called "pointless topology."

Why lock car doors while driving?

When I was taking drivers education classes, one of the "rules" was to lock your car before you put it in drive. But why?


In favor of locking:
Maybe in an area where you stop a lot, a carjacker or other villain might open the door when you stop.

Against locking:
If you are in an accident, and unconcious, rescue workers won't be able to get in.


But is there a real, honest to goodness, not based on hyped up fear, safety reason for locking the doors?