When you buy a TUXEDO, you don't just buy a laptop - we also provide a wide range of help articles and instructions that are constantly being updated and expanded.
As you can see, you're only addressing the tags as #labels following a post, whilst most folks tend to #hashtag their #articles inline as they type out their posts.
Having a facility to integrate those two methods is of great benefit and note that in my example not all #tags are duplicates between the two methods of presenting them.