What is so good or bad about conflict?

Is Conflict Good or Bad?
The answer is YES. Conflict is good when the outcome is a win-win resolution. Conflict is good when the relationship between the people in conflict is strengthened as a result of the conflict. But few people are skilled in the interpersonal skills necessary to manage conflict effectively, and when conflict isn't managed it generally goes bad. And when it goes bad it can get really bad.
The drama of conflict gone bad can have a devastating effect on the attitudes of everyone involved, and if it isn't resolved it can linger and spread like an infectious disease. The result is negativity, low employee morale, and a dramatic drop in productivity.
Conflict Management and Conflict Styles
Most people don't really think about how they approach conflict. It just happens. When conflicts arise we tend to play out our roles like scripts based on our behavioral and conflict styles. Effective conflict management can only be achieved when an individual begins to really see how her or his conflict style is actually self-destructive.

Source: http://www.conflictmanagementworkshops.com/