However! Let's be honest about this, when you get together with family or friends, do you never discuss anything political?
Maybe you don't, especially if you are in vehement disagreement about the subject, and one or more of you is known to have a short fuse. I can imagine that there are situations in real life where politics, religion, gender issues, etc.
are off limits, because they will inevitably lead to fights. And discussions in those circumstances usually are pretty bland and boring. (I mean, how long can you talk about the weather?)
But if people are reasonably intelligent and mature, there is nothing wrong with exchanging various points of view. Even if nobody ever changes anyone else's mind, discussing things helps us learn and sometimes helps us clarify our own thoughts.
What gets annoying to me is when people keep repeating the same old same old, to a degree that they are totally predictable. But I still don't think they should be banned from doing so. If they are beginning to sound like a broken record
(remember those?), others will tell them so in short order.
Saying that you never discuss religion or politics means you want to limit conversation to just exchanging dull platitudes for the most part. There are some exceptions, such as favorite movies or TV shows, but we have separate topics for those things. A topic called "General topics, or Hot Topics" is inviting all sorts of topics. And absoutely anything can be controversial.