Storing Junk

What is it with people and storing junk? By junk I don't mean their personal belongings, I mean real trash type junk. I just got back from an auction of 23 units and over half of them had nothing but junk in them. 

Went to an auction today with the same results...I'm sure most of it is people being able to clean out what they want before it gets locked out.

I don't know why that stuff is there to begin with. Same goes for food. There's never been a functioning kitchen in any locker I've seen. Why the hell would you store your rice and beans there?