When you're rude, or outright unpleasant to people like this, you are perpetuating the problem and keeping people trapped in cults.
Let me explain why. People are often born into cults organisations like Jehovahs witnesses, or the westborough baptist church. They've not known another life other than what people older and than them have told them. Or they've come into these spaces as a vulnerable person who is seeling validation and comfort. They're often denied access to the Internet and the outside world. The only access they may have to other people outside of their cult church is the people they meet when they go door to door, which they are often forced to do.
When you're rude, or dismissive, or abusive or nasty, those people keeping them there use that to that advantage. They say "look how these people treat you. Who are you going to go to if you leave? Them? They clearly hate you. You have no choice, you have to stay here with us"
The exact same thing happens when you belittle and mock and bully people on the Internet for their beliefs, or when you blame one group (Muslims for example) for the actions of a few. The elders, the people at the top, use this to radicalise people. Look, they hate you, look at what they say about peopld like you, we love you, come to us".
You say none of this is your responsibility, and maybe you're right, but do you not think the society you live in would be better if you were kinder to people instead of being rude to them, which in turn perpetuates abuse and radicalisation?
Then maybe when someone wants to leave this world they are trapped in and is trying to pluck up ths courage to do so, instead of thinking "I've got nowhere to go, the outside world is scary and they hate me' they might think "that one lady smiled at me and gave me a bottle of water after I'd been walking around all day in the heat, maybe they're not all bad, maybe they'll help me"
Just trying to show the bigger picture in case you weren't aware/hadn't thought of it. A very small but of effort, even just a smile or a polite "no, thank you" can make such a massive difference and takes a second.