Lincoln has it exactly right. Crossfit is about preparing us for the WIDEST variety possible of physical demands, with that in mind how in the world could you work on weaknesses, they are literally endless. The reason the WOD is the same for everyone is that it focuses on basic movements like powerfull hip extention.
Keep in mind, the Westside folks are oriented toward powerlifting competition - a well defined set of tasks. Crossfit acknowledges that you sacrifice maximum performance at any given physical task, in return you get near world class (or actual world class) performance at nearly ALL physical tasks. This is not an unreasonable claim given that the basics of human motion and power generation don't change from sport to sport.