The curse of information design

Scott Jason Cohen posted this rant on A List Apart. Why is there so often an "Us" and "Them" attitude when it comes to IA and Usability versus Design? I don't think anyone should feel defensive of their turf when it comes to design. Just let your design speak for itself and hope that most of the integrity stays in tact if it demmands another iteration. Hopefully, you will have the IA informing the interface design and doing Usability testing along the way so you don't have to feel that your work was too butchered. Design on the web IS a multi-disciplinary effort. There is no reason why the different teams (Design, IA, Site Developer, Engineer) cannot work together with checkpoints along the way, instead of taking your design piece and hurling it over the wall to the next person.