There are two ways to look at this question: “What’s the point of group discussion?” and “Why would you, as opposed to someone else, lead a group discussion?”  Let’s examine both.

WHAT’S THE POINT OF GROUP DISCUSSION?

Group discussions are common in a democratic society.  There are a number of reasons for this, some practical and some philosophical.

A group discussion:

• Gives everyone involved a voice.  Whether the discussion is meant to form a basis for action, or just to play with ideas, it gives all members of the group a chance to speak their opinions, to agree or disagree with others, and to have their thoughts heard.  
• Allows for a variety of ideas to be expressed and discussed.  A group is much more likely to come to a good conclusion if a mix of ideas is on the table, and if all members have the opportunity to think about and respond to them.
• Is generally a democratic, egalitarian process.  It reflects the ideals of most grassroots, and encourages a diversity of views.
• Leads to group ownership of whatever conclusions, plans, or action the group decides upon.  Because everyone has a chance to contribute to the discussion and to be heard, the final result feels like it was arrived at by and belongs to everyone.
• Encourages those who might normally be reluctant to speak their minds.  Often, quiet people have important things to contribute, but aren’t assertive enough to make themselves heard.  A good group discussion will bring them out and support them.
• Can often open communication channels among people who might not communicate in any other way.  People from very different backgrounds, who may, under most circumstances, either never make contact or never trust one another enough to try to communicate, might, in a group discussion, find more common ground than they expected.