I think there is a distinction between what we say and how we say it. Much of the time the kind of problems that kill threads is more about the latter.

There are attitudes and opinions that deserve and indeed invite strong and forceful opposition, especially expressions of racism etc. They get that, and quite right - but there are different ways of doing it, and we need to be careful in how we do it. And we also need to be cautious in interpreting what someone has said as going further than what they have actually said.

We may think that a remark made by a poster implies racist attitudes that they have not actually expressed, but we should be very careful about building on that. Even if we are right, it's falling into a trap.