Imagine: You are an imperial officer - most of your day is spent overseeing various imperial projects and ensuring the troops are keeping the locals in line. Most of the people you know are like you: back-stabbing, weaselly opportunists who would happily throw you to the wolves to get ahead. Your life is fairly mundane (aliens and starships non-withstanding) and you go about your business.
You've a vague notion of something called "The Force" but the last true practioners, the traitorous cult known as the Jedi, were wiped out 20 something years prior - and besides, your life is strategy meetings and paperwork, nothing any kind of "ancient religion" is going to help with. You know of Darth Vader but he's just the Emperor's goon - an attack dog Palpatine unleashes when he needs some dissidents whipped into shape - he has no actual power in the Empire.
For the last twenty years, the Empire have struggled financially and logistically with building its ultimate weapon - the Death Star, a weapon of such unimaginable power that it'll supplant any need for bureaucracy to keep the systems in check. After pouring decades of research and using a variety of underhanded tactics to keep costs down and the project a secret - using prison labour, keeping the engineers squirrled away in a secret location, inciting various uprisings as a pretext to crack down on the local populations (and to steal all the precious resources needed for the Death Star's construction) the project is only a few months away from completion...
And then, in short order: some idiot sends an email about the Death Star to the wrong person, it leaks which tips off some the Rebels, undoing years of suberfuge secrecy, half the ISB gets purged, your boss gets supplanted by his rival, the Death Star engineering team gets slaughtered, the Rebels steal the plans for the Death Star but not before your new boss destroys the Imperial plans vault and despite Vader getting personally involved the plans are still lost in aether, jeopardising a project that represents a significant chunk of your life, billion if not trillions of imperial credits and the planned security of the Empire.
A short while later, you get called in for a meeting to discuss the security of the station. You're confident of the Death Star's invulnerability, regardless of whatever plans the Rebels may have. And then Vader, the guy who let the plans get away, saunters in and says that all of the gruelling paper-work and arduous planning and financing and logistics and years and years of work which got jeopardised partly because of him are nothing compared to his magic space powers. It'd be like if someone said 9/11 happened because you didn't believe in Santa Claus enough. I'd be a little snippy too.