If the spelless ranger was just a wilderness warrior, sure. But the ranger should be more than that. They’re a survivalist, a tracker, an ambusher, a monster hunter… And they should be preternaturally capable of all those things.
Ultimately I think this comes down to the same fundamental point of disagreement as any casters vs. martials argument does: should it be possible to exceed mundane limits without casting spells? If no, obviously the ranger should cast spells. If yes, then doing so without casting spells is going to be more thematically appropriate for the ranger.