Because in most cases, what is assumed to be “truth”is subjective. If you’re talking political. More often things are blurred with regards to truth as most things tend not to be empirically true, but instead, emotionally true.
For example;
“All conservatives are Nazis!”
This is inherently untrue. Yet I see every day- people who believe this to be the absolute truth. Same thing with-
“All liberals want to do is make our children gay!”
Also untrue. But when you try and correct them, they will almost always entrench themselves within their own version of the truth and disregard any form of critical thinking.
This is why asking questions is important. All conservatives are Nazis may actually be true if the person merely equates conservatives with Nazis, the proposition a mere tautology. Same for liberals trying to make kids gay, where people who make kids gay are liberals.
And by asking questions, trying to understand someone else, both parties can engage in critical thinking.
I think it's wrong to think that critical thinking should spontaneously arise because someone's beliefs are challenged. That's never how it works. Rather, one person has to be vulnerable and ask, "What do you mean? Help me understand where you're coming from."
That's sort of exactly the point. People believe it to be true, and it's sort of impossible to prove them wrong. Nature vs Nurture still isn't proven either way, regardless of how strongly you feel one way or the other.
The simple fact that someone believes it's possible to "make people gay", almost necessarily leads to them believing there are people out there actively doing it.
Sure, but the problem isn't fundamentally different from any other based on different views of how the world works, which is important. It means that it's subject to the Socratic Method, for example, or any other method of inquiry that helps people explore their own beliefs.
What it means to "make people gay" may just mean having LGBTQIA+ stuff in the general area, inviting others to come out and normalizing the behavior. I'm willing to bet that's exactly what it means based on what I've seen and read. And even if I disagree with that perspective, it makes way more sense than literally forcing people to become gay. And that's definitely a step forward than merely thinking that person is as dumb as a box of rocks, because now understand how they're as a dumb as a box of rocks.