With the Dev's announcement that the surface scanner will return the materials to be found on a planet, carrying a DSS will now become a necessity for many people not actively engaged in exploration.
Why? You can already find the location of planets for whatever material you want using the Herald newspaper. Its like being able to use the ADS to discover planetary bases: its possible, but far from a necessity. IMHO making modules that were exclusively useful for only one select group of players be more useful for others is a good thing. My current 'all-purpose mission runner' is an FdL with five meager slots. It works great. A Cobra mk3 (or even better mk4), or Asp Explorer makes for a great multi-purpose ship.