If we're going to be pedantic, I would note that all nonstops are direct, but not all direct flights are nonstop. Agree that AA (along with UA and DL) seem to have very few direct flights with a stop, so much so that many people use the terms synonymously. However, WN still runs direct flights with stops regularly - they are modestly better than a connecting flight for a few reasons (don't have to deplane, short connection that you can't miss, etc).