Without knowing which incident you refer to above, there can be many answers to your question.
It is my belief that a procedure that is largely percieved as unnecessary or impractical, would over time tend to be disregarded. It might be because it it; or it might be because the underlying reason is not clearly communicated.
Take some examples, both from the flying, and non-flying world:
- You are driving your car in the US, where STOP signs are more common, and yield signs are less common. Approaching a stop sign, coming onto a crossing road with good visibility in either direction, and absolutely no traffic, you decide that you will keep a slow speed through the junction instead of coming to a complete stop. On one hand you know you are in violation, but at this particular junction, you positively determine there will be no danger, and you will not get caught. Does this stop sign help reduce accidents, in that particular junction, more than it creates a disrespect for stop signs, possibly causing them to be overlooked at other junctions where they may be very important?
- A nurse may, at some places, be required to show other nurses whenever remaining quantities of sedatives are disposed of (ie if you put half a shot of morphine into the sink, someone has to witness you). The hospital management has imposed a rule that this procedure shall now include all medication. However at a that particular ward, there is a shortage of nurses, and in with the patients interests in mind, that rule starts slipping. The nurses see that it is impractical to call on another nurse to throw away 1/2 tablet of ibuprofen/paracetamol/other, when his colleague is already busy. After a while this rule slip grows to include potent drugs such as morphine, and one day, when management finds out that morphine is being disposed of, they now tighten the screw and mandate that all drug discarding shall be witnessed and signed for by another staff member. Will this procedure be helping?
- An airline that prides themselves in high operational and safety standards, requires all their pilots to memorise ALL checklists, including abnormal and emergency drills (let's say a total of 100 checklist, with on average 3-4 items each). On a simulator check one pilots balls up the engine fire after takeoff and is reprimanded. He argues he did the best of his ability, and he then starts reciting other abnormal and emergency checklists, to show his commitment, and pride in his work. Whose fault is it that he ended up in a smoking hole?
There are other various reasons for procedure not being followed, but I think the above is very important to be mindful of when designing procedures. As long as there is no major grievances towards superiors, I think most people as willing and able to follow a procedure to the best of their ability; but such procedures must be smart, practical, and thought-out. I'm not defending the above three situations: you SHOULD stop at a stop sign, you SHOULD show the paracet to another nurse and have him sign for it, and you SHOULD memorise the engine fire checklist. I'm just saying you have to consider the human factor; you cannot write procedures for them as you write software code for a computer.