People already not knowing how to play their jobs with things that are currently in the game isn't really a very good argument for why something like that should be implemented. It would only give them yet another way to be completely oblivious of how to play. I also doubt it would get more tanks/healers in the duty finder queues; it'll probably be the opposite, people still playing their DPS classes and getting easy levels for tank/healer without any of the work or stress of playing them.

And I don't know what game you're playing, but content from level 1 to 70 isn't "dead". That makes literally no sense to say everything except endgame has no one playing it. People are always doing dungeons, raids, etc. and running around in early zones. Maybe if you wander around a bit instead of AFKing in Rhalgr's Reach you'd see that.