There is a lot of (arguably -- which I won't argue too much) FAKE and/or misleading science regarding protein intake.
For instance, too much protein is bad for the kidneys .... when in likelihood, most people are probably not getting enough protein.
As with all health matters, it requires sifting through both sides of the argument and it's complicated and hard work, so most people give up fairly quickly and just take in the first information they find.