Why is whataboutism so prevalent?

Disclaimer: This is not a specific response to or charge against anyone on Fluther nor am I claiming to have entirely avoided this myself.

Whataboutism seems to be the current political addiction. “Y is bad. X group does Y”. “Well Z group does Y too!” So what? Who cares? That doesn’t suddenly make X group doing Y okay. If the group you hate does something bad, that means it’s okay for the group you like to do whatever they want? Two wrongs don’t make a right. Unless hypocrisy is the subject of the discussion, it’s often irrelevant to bring it up.

It’s a way to distract from the subject at hand, to distract from discussing the morality of the action.

I’m starting to think whataboutism is human nature—from a kid in trouble hoping to get out of it by listing their sibling’s crimes to the current political climate. Do you find an instinctive desire to say what about the other side when your side is accused of wrongdoing?