I'm wondering whether it is the editing of the show, which is making them look a little dim?
Yesterday for instance, 1 team PM spent a day tasting wine, for no obvious reason (the guy deals in wines, so there is nothing he would've learnt by spending a day tasting wine, that he didn't know already).
Also, we never see what the brief actually says, ie. it is never read out in detail, so perhaps there are juicy bits of information that would perhaps provide a different slant on how the task is performed.