Oliver Burkeman makes an excellent point about the Simple Sabotage manual that pops up on the internet every now and then. Purposeful stupidity is, basically, about complete obedience to the rules. If following the rules causes disaster, there's probably something wrong with the rules, or even the idea of having them.
"We’ve all fumed about customer service reps who refuse to be flexible. But usually the real problem is that they’re working in organisational structures that permit zero autonomy. Too often, managers assume the key to improvement must be clearer procedures and standards, more exactingly enforced. But when your management philosophy encourages the kind of behaviour that US intelligence services once sincerely believed might cause the collapse of nations, perhaps it’s time to reconsider."