Not everyone likes having their beliefs challenged. It makes us feel threatened on a deeply personal level and compels us to seek consistency, so we can continue to function with sanity in this ever-changing, chaotic world.
Take a meat lover, for example, who agrees that animal cruelty is wrong but goes on to include fish and pork ribs in his diet. Or a person who cannot stop smoking even after knowing that it is harmful to their health.
Coping with contradictory ideas — also known as cognitive dissonance — can be mentally stressful, and people tend to find consistency by rationalization (accepting new information), confirmation (sticking with old ideas), or blindly believing whatever they want to believe.