User blog comment:Semanticdrifter/Understanding Attribution on Wikia/@comment-1038387-20140109214638/@comment-4811793-20140109221150

That's a perfectly valid approach. Even if the license allows content to be reused, it does not compel a community to allow it. Local wikias are definitely free (and encouraged) to set their own policies. There are definitely times when being able to reuse content makes sense, but if the zero tolerance approach works for your community, great.