Ockham’s razor is really useful: Generally, the simple explanation is the most likely to be true. Don’t invent complicating factors when none are necessary.
“It’s simple” is probably correct when describing how any individual mechanism works.
[For example, UFOs are unlikely to be piloted by aliens from light-years away, who just happened to show up in that period in between our invention of airplanes and the widespread use of digital cameras. It’s far more likely that they’re simply unexpected events that we turn into complicated stories.]
On the other hand, systems–where there are multiple mechanisms at work–are almost never simple. In those cases, it might be more useful to understand that, “it’s complicated.”
When an unexpected event occurs, we look for stories, coincidences, supernatural causes and other forms of solace to explain something that frightens or surprises us. But unexpected events are usually caused by simple mechanisms.
How we react and respond to these events as a culture, on the other hand, is complicated indeed.