Why does a class need its own schtick? Because a thematic concept needs mechanical versimilitude, and if other classes schticks can't fulfill it, then it needs its own.
Now, admittedly Ranger is my favorite class, and 5e's is my favorite implementation. Although it is a bit lacking mechanically in combat, I believe thematically it hits all the benchmarks of what a Ranger should be. It just needs a bit of tweaking like fixing a couple of class abilities, fixing the pet option, and adding a few more thematic spells that are unique to the class.
As for magic, in my opinion I don't see how a Ranger cannot have it with the assumption that in D&D it is a known fact that magic is a part of the world, and that includes the natural world. Now Rangers, attuned to nature as they are, should be able to slightly manipulate this magic. Not to the extent that a Druid does, who has given himself up completely to nature as a metaphysical concept and acts as its avatar of sorts, but as someone who uses nature as a tool in his role of ultimate survivalist, tracker, and woodsman. This is what should differentiate him from a similarly themed Fighter, Rogue or Barbarian. Now this magic may be subtle, like goodberry (which is an excellent analogue of herbalism) and pass without trace, or overt like spike growth and ensaring strike. Magic simply represents the Ranger's mechanical ability to thematically surpass a non-Ranger in a natural setting.
Now you could argue that a ranger could be built through multiclassing or a prestige class, but the first is clunky and an optional rule, and the second is still in the UA stage of development; and, at the end of the day, a Ranger is a very unique, specific archetype, ergo its own class with its own schticks.