Everyone is different of course.
There is seemingly nothing I won't talk about, but, at the same time, there are no shortages of things best left out of the topics list with me if you can't handle the blunt truth as seen by me as well.
Some times, it is not me that has the problem, and I won't mind delivering it that way too.
Thus, some times people will get told by me to not go there, if they seriously don't want to get upset.
Some topics simply push too many of my own buttons too. And the best way to get your head ripped off, is to put it in the lions mouth eh

My Facebook for instance, I had to remove a person I call a good friend, simply because they couldn't see the truth of Facebook, you make comments, and others reply to the comments. The thing is, he had family confused and confounded by 'me'. And it was , well I am not hiding who and what I am, and I comment on the things people say and show on Facebook. So I told him I was dropping him from the list, we parted friendly, but it was sad all the same. But he likes to comment on a wide range of issues, and I have strong feelings on a range of things. And no, I am not going to just say warm fuzzies to the nice things and say nothing when something bothers me. And that was the thing, he wanted me to refrain from being negative. Sorry, I don't let people write my parameters on my own Facebook page

That's how Susan's place differs. Here it is her place, her rules. If I don't follow them, being told to leave is a logical result.
My Facebook, my rules

I have a limited list of friends on it. I don't go hunting for people just because they have some vague connection to me through a friend of a friend of a friend that read the same book
I really only have one rule on Facebook. If you add me, the entire planet will see your material. I make everything public, I hide nothing. If you don't want it known, best not mention it on Facebook eh.
I have noticed though, some times with internet text only time delayed methodologies like forums where the entire cast of persons on a thread will not be interacting in real time, conversations can become out of sync or they can devolve into more than one conversation with persons coming and going at unpredictable rates. And in the process, I have found some times all you can d is state an opinion, be on record as having supported that position and then, what more is to be said? Some threads get to be little more than a dog chasing their tail with persons eventually repeating themselves and saying the same comment just different assortments of words.
That, or it is just a case of some people honestly think if they post the last comment, they win the argument

I have watched grumpy old men beat on a topic that was long dead, all so they could manifest some form of internet victory it would seem. That grew old real quick with me