Leatherhead
Possibly a Idiot.
1 - If the defender's role was self defeating, you could do without one easily.
This isn't the case. IMO, the defender is the most sorely missed role in a 4 man team if he is absent.
I would have to disagree, it is actually easier (and surprisingly more fun) to play a ranged group without a defender, than it is to play such a group with one. Granted that is a non-standard group, but a controller is far more useful than a defender in those situations.