I'm sure it can be true in painting, but certain accidentally out of focus, over-exposed, or even blurry, photos can have an amazing quality you wouldn't have captured otherwise.  Here are examples I've taken:

Over-exposure: 

Soft Focus:

Motion Blur: 

Motion blur is my favorite way to make an image jump off the screen.  The ones I like best have some blur, and some focus.  This photo I took at a fashion show in LA shows her hair and shoes blurred slightly, but not the rest of her.  It gives the illusion of movement: