A case in point: the helpset file (with an .hs extension), which is one of the files required by a JavaHelp-based helpset, isn't recognized by default by the IDE, so is treated as a text file. However, I want it to be treated differently to text files, so I need to create a file object for this. I want it to have its own actions (right-click contextual menu), its own syntax highlighting, its own code completion, etc. In effect, I want it to be a first-class citizen. An easy way to see whether a file object is a first-class citizen is to see whether it has its own icon. For example, take a look at my helpset file here, with its own special little icon:
And what exactly did that template do for me? Well, you saw the result above, but now take a look behind the scenes. These are the files that are generated straight out of the box (everything starting with "hs" below comes from the New File Type wizard, the icon was selected in the New File Type wizard, and the layer.xml is also magically updated):
Now that your file type is recognized by the IDE so painlessly, you can focus your work on what you want the file object to do for you -- instead of wasting time at the start thinking about what you should do for the IDE to recognize your file type. And that's the way it should be.