People trust what they FEEL good about. If two equally professional looking sources say different things. One says "you are doing something wrong, you will have

People trust what they FEEL good about. If two equally professional looking sources say different things. One says "you are doing something wrong, you will have to change how you think" and the other says "someone else is doing something wrong, you are thinking correctly" then they will trust the second source. Even when the amount of evidence grows for the first source they will trust the second. This is especially true if they will lose face for having trusted the second source.