They would rather back into a parking spot surrounded by stationary obstacles than back into a parking lot or road which may contain pedestrians or other drivers.
I'm not saying _I_ back into spaces. I generally drive into spots and reverse out of them. However, I admit that what I do is a tradeoff where I take on risk in order to have a mechanically easier time entering and exiting the space.
That's true, but what GP is saying is that when you're pulling out, you are traversing the part of the space overwhelmingly more likely to contain passing pedestrians and vehicles with full visibility.
And then some parking spots require parallel parking which is best done via backing up anyway.
