I feel like DW is most strongly fiction-first, and can be story now if a group want it to be. It has the architecture, but nothing really forceful. MotW is somewhat similar. I've seen and experienced both games played in different ways (and read about that anecdotally here too.) Actually I believe @AbdulAlhazred outlined some elements that are all too easily grasped insufficiently strongly, in another thread.As with many things in D&D, there really isn't a line that can be identified. When someone says something is or isn't D&D, what they're saying is, "This doesn't trigger my gut-feeling recognition of 'D&D' things." It's completely personal and unstructured. Which is fine, if all one wishes to do is express personal preference/interest/etc. Issues arise when one starts to reify such things--I'm sure all of us have heard of at least one example thereof.