Agreed. The more they decline the higher the lockout they should get. For example: the first time they decline they should get a five minute lockout, when that lockout is done and if they decline another party they should get a ten minute lockout, then fifteen for the third time they decline, etc. It should punish someone for being lazy, so much so that it becomes more time consuming to abuse the DF than to simply join a group and finish a dungeon.