It is a very difficult thing for some people to accept their fault.it is either they have a very good reason for doing the wrong thing they did or they find somebody else to blame their action on
Complaining prepares the ground for passing blame. This provide an escape route from taking responsibility for our actions, and the problems remain where they are,or get magnified as time passes while you are busy complaining and blaming others.
Just think about it: you happily blame others for your failures, why don't you give them credit for your successes too?
That's why you don't have to be blaming them for anything at all