We live in a society with an overwhelming amount of information. We can't assess every piece of information we are given so we have to use heuristics to make decisions - those heuristics are often fallible. More expensive is not always better. Pharmaceutical doesn't necessarily mean high quality (or anything), and the known brand is not always the best.
Couple this with the fact that people have lost their ability to actually reason and form their own decisions, and we have a nightmare. Hate to say it, a lot of people on here do the same thing - "Oh, this study says this, so it has to be true" - yeah, well, that study may be a study, but it's not science because it hasn't been interpreted using logic and reason.
Another one I'm facing now - "reduced salt intake is good for you" - I have an elderly grandmother who has been prescribed a restrictive salt diet by her doctor, an aunt who takes this even further because of fear, and the result is that my grandmother winds up in the hospital every 6 weeks with tremors and confusion, etc. because she probably is sodium deficient. But the doctors know what they're doing, despite the fact there is no reasonable study, EVER, that has shown salt intake negatively impacts blood pressure.
It's everywhere. Sorry for the rant.