If you talk someone out of their group's values, you might destroy their entire life. Talking someone out of their religion is a "win" until they get shunned and lose everything they have. Are you still in the right then? What does the "objective truth" matter if you're just ruining peoples lives?
Change someone's mind on guns or abortion and you hurt them! It doesn't matter which side they start on or which side you convince them to. You're ripping and tearing at the very fabric of their social life.
Some people are unable to change their minds, but some people can't change their minds due to circumstance. It's really important to understand this before convincing anyone of anything.