Some engage only to criticize never to contribute. It rings their chimes, floats their boats, turns them on. Why?

Hmmm...that reminds me of someone.

Your hostile, negative questions tend to invite those kinds of responses.

Criticism can be an important change agent, but only if the person receiving it is open to making a change. Constant criticism in the face of constant denial is the mental equivalent of banging one's head against the wall.     

So why do you do it? 

probably cause they like to do that