"Assume good faith" is not one of those decisions where either option is fine as long as everyone agrees to stick to it. It's a basic rule of politeness, very similar to the golden rule - if you assume bad faith and act accordingly, people will readily see bad faith in your actions too.
For instance, if I write a post complaining that busing is bad for the ...
The key here is to be shrewd about what the author is trying to do. Let me illustrate this by using spam.
We allow users to post links to SO/SE. There are good and bad reasons to post links, but there's also a grey area. On other sites a question like this would be permitted
I have some code not working
Some code here
You can see it ...
How to deal with Dog Whistles
Are you sure it's a "dog whistle?"
If there's not an easily understood charitable explanation, it's just bigotry and violates the code of conduct. If it's not a real dog whistle, don't call it a dog whistle.
Be nice, assume good intent on the part of the other person.
This is a bigoted dog whistle. I'm ...
In this day and age, you can reasonably assume good faith on every Stack Exchange except this one. I agree with divibisan that "unintentional bigotry is just as hurtful as intentional bigotry". But I disagree with the idea that we should always seek to fix such posts, because doing so means that bad faith users may end up getting upvotes. If that happens ...