People are easily manipulated morons...
... who like to live in an echo chamber to hear things they already believe, regardless of the truth or facts.
If course businesses exist to exploit this fact. Advertising and political manipulation of the public has existed for years.
Now if the public learnt critical thinking, used fact based analysis and were open to changing their opinions based on evidence not their belief or emotion then it would change overnight.
But like I said - people are morons.