Part vs PartDesign debate is an interesting one indeed. Basically such debate doesn't have much to do with existence of modules like Ship, FEM, Arch, Path ... in FreeCAD by default. There likely was a (slim) chance Part workbench would get superseded by PartDesign (NEXT) workbench. But that more or less didn't happen, as both serve a different purpose now. In addition a lot of functionality and projects out there depend on Part workbench. Therefore Part vs PartDesign debate will likely still be here in foreseeable future. New users therefore do need to grasp on why both exist, that much is true.