#magic People have always believed in silver bullets ... even while denying this belief. Advocates of this or that technology often spend a lot of time refuting the claims of earlier technologies to be silver bullets, while modestly and disingenuously avoiding making such claims for the technological breakthrough they are championing.
But the modern notion of silver bullet is based on a misreading of fairy tales and ancient myth. The silver bullet (or any other magical weapon) is not a general-purpose quick fix, providing generic protection against all evils. It is a precisely targeted weapon, providing overpowering force only when used by the right person against the right opponent at the right time. In the wrong hands, the weapon either fails altogether, or proves dangerous to the person using it.
The silver bullet itself has a very specific purpose within horror fiction - to kill or subdue vampires [Monstropedia: Vampires]. As Sam Leith explains, vampires and zombies represent middle-class fear of the upper and lower classes respectively. In other words, silver bullets kill those born with a silver spoon in their mouths. This is based on the important magical principle of similars - the notion that the solution mirrors the problem. As in the belief that rabies can be cured by a hair of the dog that bit you, or that the best cure for a hangover is another drink.
Interestingly, the belief that the solution should mirror the problem happens to be popular among IT folk. For example, they may try justify the use of object-oriented software by the curious argument that business "is made of objects", or they may use "structured" tools and methods that smoothly and painlessly go from a descriptive model of "the business" (AS-IS or TO-BE) to a "logical" system architecture or system design, without tackling the difficult design tradeoffs addressed by real design thinking. This is one of the reasons why New Systems Don't Work.
Meanwhile, the reason why magical thinking survives is that it sometimes works. Primitive man believed that if you want something to fly, you attach a symbol of flight. So they tied feathers to their arrows. As luck would have it, this improved the aerodynamic qualities of the arrows, thus confirming their superstitions.
Modern man is just as superstitious as primitive man, but just about different things. Many so-called best practices are merely optimistic attempts to replicate the lucky successes of the past.