Yes, I read the explanation. The actual explanation has no racial component. The sign, and NPR prominently featuring the sign, implies that the explanation does have a racial component, even though it does not. Hence my complaint.
Oh, you asked why the sign was in the photo as though you thought it wasn't associated with the story in any way. It gives a little background context for the type of Catholic church whose pastor was interviewed. I don't know if you've spent much time in various Catholic congregations, but the sentiment that racism is bad is not echoed in a disturbing number of them. It's unfortunate that you are offended at the sign being used as a framing piece for the article.
