"Success has many fathers, but failure is an orphan."
It's basic human nature to want to be associated with successes, and distance oneself from failures. Everyone wants to think of themselves as winners. Blamers -- the fifth behavior managers hate to see in their employees -- take this to an extreme. They will find a reason to fob off the responsibility for anything that didn't go well to someone or something else -- often times the manager they are working for.
A typical Blamer exchange might sound something like this:
Manager: Why haven't you gotten that project done?
Blamer: You didn't tell me it was a priority.
Manager: We discussed it at the staff meeting. Everyone knew we needed this done ASAP.
Blamer: Sally hasn't given me her input yet.
Manager: Why didn't you go get it?
Blamer: Because of the other project you told me to work on...
And so on, and so on. No matter what the manager says, the employee will not take ownership for any shortcomings in their own performance. They always find an externality that prevented them from doing what they were supposed to do. As a manager, I always preferred to hear the employee say, "Jeez, I guess I forgot about it.", or even "I had to leave early yesterday to take my kid to the doctor." Those kinds of things can be worked around in the future, but flat out denials and blaming can not.
And some managers, particularly those who are less experienced or those not good at identifying a Blamer, will internalize the employees critiques, taking more and more on their own shoulders until the situation becomes downright absurd. If you're a manager, and you feel like you're responsible for everything, and your employees have very little on their shoulders, you might be getting played by one or more Blamers.
Now, I'm not saying taking responsibility is easy, but it is what adults do.
So if you find yourself frequently blaming others or external forces for things not happening, you should try to change your thinking. Look at your own failings first. Take ownership for those things that are in your control. Be a grown up. Otherwise, you look like a child to your managers, and you significantly reduce their opinion of your performance.