Why? Because there are a lot of them? The list of scientific beliefs I take seriously is at least a hundred times as long, going by the books on my shelf and those in the library. I am not saying that I never made a mistake, I am only human but the probability that a significant fraction of these are false is incredibly low. Most of it is filled with alternative medicine and ufo nonsense.
A couple of years back I stumbled across this diagram on reddit. Since then I've kept a list of all illogical arguments, quackery, irrational ideas and similar nonsense, to pass the time. The count as of today stands at 1229 irrational ideas (a few could be debated perhaps). Hopefully you'll have a laugh or two! Any additions let me know!
Link to the list:
https://docs.google.com/spreadsheets/d/1T3HQ6TnCg6Q44WzpJPFxLvfqbfvKmT5RqvpGI3ji1y8/edit?usp=sharing
And the original diagram: