You are right about them not saying anything offensive, but reason of not saying anything offensive is that, these are for TV viewers, where organizers have no control on who watches them. In private settings, what goes on, don’t ask.
I know this from my personal experience, first hand knowledge. One of my good friends and a flatmate for 2 years, is Shia. why he avoids these majalis, and why his family condemns him is exactly because what they say in these gatherings, and he doesn’t like to participate in hate mongering and name calling.