"How do you feel about people disrespecting their parents?"
Children will treat you the same way you treat them. They are master mimickers. So, if you scream and swear and them, then guess what ... Parents need to teach their kids how to speak respectfully, by speaking to them respectfully. It's basic child psychology. Google it.
There's a difference between an adult speaking to their parents in a blunt and honest way, and just being outright rude. I don't think it's very nice, but when you are an adult, you're going to say what you're going to say. I've heard some of my friends and family speak to their parents so horribly, that I am embarrassed to be with them, but I can't force them to understand that there is a better way of communicating. And I also know some older parents who are really just so freaking ignorant, that it's almost impossible to speak to them like a normal human being because they wouldn't understand. It is beyond their level of comprehension.
Personally, I think it's better to be kind than to be right, regardless of who you're speaking to.
Unless it's just totally fucking retarded. Dinosaurs were real.