As I see it, a defender whose goal is "get things to attack me" still has to pay attention to whatever the other side of his coin is.
Attack me, because you're not going to be able to hit anyone else.
Attack me, because otherwise I'm going to hit you again on your turn.
Attack me, because if you try to move away, I'm not going to let you.
Attack me, otherwise I'm going to teleport you back over here and you're going to have to walk through the mage's wall of fire again.
If a monster flat out refuses to attack a defender, that defender should be steadily forcing the monster into a situation where the defender can no longer be ignored.
In the end, everyone's fun can get rained out by DM whim. At that point it's not a fault of the game or the mechanics. Archers can spend weeks in tight, twisty hallways where they never get to use their bows effectively. A wizard might pick up fireball, only to discover that he's never going to fight another swarm or minion ever again. There are a million ways that a DM (for good or ill) can counter what they see as an imbalance of power. But, if the DM is trying to keep everyone entertained, you should expect them to not abuse their DMly powers and continuously stick players in situations where they feel unloved.
I don't know if you caught it upstream, but when my group started playing 4th, my defenders ended up bitching because whenever they marked something, all I'd have the marked creatures do was attack the guys who marked them. They felt cheated cause they never got to use the other half of their mark powers, and they were bored by being the only guys who ever took any damage. All or nothing stinks.