Those teams weren't nearly as deep as the one we have now, and a much better staff all around.
The latter had a much greater effect, though.
To put it bluntly, 2009's defense under Jon Tenuta actually had decent players, but with Tenuta calling jailbreak blitzes every down, and allowing teams to complete those intermediate range throws every time, he was the reason why we couldn't get decent field position.
Had he simply played a more conservative defense, that should easily have been a BCS Bowl team.