[IKE]

GBK,
Ultimately the GDC gives us a game with rules about scoring and qualifying and ranking. Adding the constraint "this is the primary objective, therefore teams should do this" is adding an artificial constraint.

In 2011, you could win most matches with a minibot. In 2010, the mere act of hanging regularly was worth about 2x the average team score. Ramps in 2007, Human players scoring over 50% of moonrocks at the championship in 2009... Pretty much every year has an aspect were excelling at a less prominent task is more valuable than poorly scoring at the main objective.

Now back to your original question if the Co-Op bridge was overvalued, I think the Co-Op had some distinct issues.
1. If you opponents chose to not Co-Op, you would loose ranking.
2. At events where the Co-Ops were over 50% (Troy, MSC, and Championship) strange things occurred where teams got giant Co-Op scores without Co-Oping themselves.
3. Co-Oping dissappeared in Elims, which made the game a bit odd as it changed gears from qualifying to Elims. (some people like this, but I think it confuses spectators and many teams).