So when I buy a 600 lumen LED bulb that burns 7 W, I'm not only getting hosed because they're overdriving the LEDs but I'm also using over twice as much electricity as I could be?

Not really. The "overdriving" (really just choosing a higher point on the current/output curve) is part of how they deliver that 600 lumen. If you put half as much electricity through those same LEDs they would in theory last longer. You could deliver 600 lumens for under 7w (but not as low as half) using a more expensive array of LEDs driven less hard and still get the longer lifetime, but it's not easy to be really sure whether the upfront cost and embedded energy would always be justified.