The issue in my opinion is one that plagues most discussions in the world: fanatism.
For example, when I was debating on the race thread who was to blame for what on the Hamilton/Verstappen incident, there were plenty of people willing to read my opinions and post a counter argument, as pointless as the discussion was at that point. To me that's fine and it's always nice to read the other side of the story and have people from the other side understanding your point.
The problem is there are always those using every kind of fallacy and fanatism to take away from the quality of the conversation, like "a former F1 driver said this, so he's automatically right and you're wrong because you're just a nobody" or "driver X did something wrong on this and that occasion, so he's automatically wrong on this one as well", or even "you're just a fan of Y driver, that's why you're on his side". I mean, at that point it's just sad.
Pretty much every time I try to defend a driver on an incident I have to begin with "I just wanna make clear that I'm not his fan and I'm actually a fan of X and Y driver", and I shouldn't have to do that if I was in a rational environment.
So to me it doesn't matter what subject people discuss, even the more controversial ones can be talked about with no issue, the problem is when people use anything other than logic to try and prove their point.