All fair points. But at the end of the day the real issue is not the 'mechanic' but the 'people'. Any mechanic can eventually be exploited (we are still suffering from the Garuda exploit despite being fixed ages ago). The only real solution is to avoid other people.

Either we create a world where we do not deal with other people, or we create a world where other people are good. Which is easier or preferrable? ^.^;;

If we turn everything into instanced content, add content finder with three levesl of difficulty on it, then there will be a lot less 'problems'. But then it will feel like playing a single-player game with some slightly better than standard AI companions.

Personally I would rather just accept the world as having both good and not so good people in it who (ocassionally) make it less fun, then resort to such strict and drastic changes that turn this into a very different experience.