Denial helps us to pace our feelings of grief. There is a grace in denial. It is nature's way of letting in only as much as we can handle.
The five stages - denial, anger, bargaining, depression, and acceptance - are a part of the framework that makes up our learning to live with the one we lost. They are tools to help us frame and identify what we may be feeling. But they are not stops on some linear timeline in grief.
We point to our unhappy circumstances to rationalize our negative feelings. This is the easy way out. It takes, after all, very little effort to feel victimized.