Here is what I purpose Anet should consider doing to try to reduce it:
The "Deserter" Title.
- Whenever a player leaves in the middle of a pvp game (whether that be an arena or a competitive mission) before a victor has been declared, they will gain a point towards this title.
- For each point in the title, players will receive less faction for both balthazar and alliance. How this is calculated I leave up to Anet.
- To remove the points from the title in order to remove the penality, players have to stay in matches to the end.
- To further promote staying, players can gain points for a new title of "loyality" in which they can gain extra faction based on the number of points in the title.
- To prevent leechers from exploiting the loyality title, they have to actively participate in the match. It's up to Anet how to determine when a player is "active" in a match. I would suggest that players get kicked from a game if they fail to move their character after 1 minute of standing still and not using skills and/or initiate an attack.
Ok, just my thoughts on how to deal with this problem. It's about time Anet did something about the whole leeching/leaving situation and I hope this idea would be a good step in the right direction.