Theories are what drive science. Without theories, human knowledge does not advance. But not all theories have merit.
Consider the ancient Greeks. They noticed first that the mood orbited the earth; that is was on some sort of crystal sphere. The shape of the moon cycled every 28 or so days; this defined the size of the sphere.
Then they noticed that some “stars” seemed to move around the sky and did not stay in fixed locations. They called them “wanderers” and developed a concept that these wanderers rested on even bigger crystal spheres. Since the moon was on a sphere around the earth, these other spheres also had to be centered on the earth.
Everything was good until someone noticed that Mars every once in a while seemed to move backward. The explanation was that maybe Mars did not rest on a sphere; rather, it wandered in a path close to the sphere and this made it only appear to move backwards.
Everybody was happy. For a while. Until some crazy person said the Sun and not the earth was what everything orbited and the orbits were of different periods which could also explain Mars in retrograde.
The point is that somebody started with a theory, and when anomalies were found the theory became more and more complex until Copernicus finally said “Wait! There has to be a simpler explanation.” That revelation took only around 2000 years, and it disrupted the “settled science” of the day.
In general, we like to slice through BS with Occam’s Razor – that simple explanations are probably closer to the truth. The more complex a theory, the more likely it is to be wrong. You see, it is far easier to damage a complicated machine than a simple one. And it is far easier to refute a complicated theory than it is a simple one.
The problem with “science” is that often the person with the complicated theory is very, very good at selling it, because the people he is selling it to slept through those boring science lectures in college with a hangover that would make death a preferable option because “I’ll never need this.” These salesmen are so good at selling their Rube Goldberg theories that you want to believe. You need to believe. Because it’s a crisis and we’re all going to die if we don’t do something NOW! And when enough people have bought the snake oil he is selling, anyone who dares to question is shouted down, slandered, and labeled a “denier”.
In societies, we prefer that people more or less fall into line by adhering to accepted norms of thought and actions. Being labeled a troublemaker is not something to strive for. We have our reputations to think of if we want to be taken seriously, and we all want to be taken seriously.
So when someone is trying to sell you a complicated theory with dire consequences if you do not fall into line, they are essentially asking “Who are you going to believe? Me or your lying eyes?”
Personally, I prefer to believe my own eyes and experience.