I see it this way....

If a single tank or healer can carry a failgroup in a 2/3 or 3/4 dungeon to success, they deserve those quick myths. As a tank, I find it far more rewarding to help such groups (usually new players) through these obstacles. Perhaps what really needs changed is how dungeons are flagged as partially complete. If checking the box meant more, those queued for new dungeons would not see the LFD spam to begin with.