Why? I'm actually curious about what the difference is. I always thought that "primal" was a synonym for "powered by nature".
Well, my understanding of 4e anything is extremely limited, but I am led to believe that that is how primal was explained.
I think maybe part of the disconnect is with the fact that Druids and Barbarians were both considered "Primal" classes. When I think of those classes...there is just nothing about those two that I see common ground on.
For me the power of "Nature", as separate from "Primal" or "Divine", is that it taps into the forces/energies of the physical natural world. Not "Spirits of Nature" or "Ancient whozits that you call upon"...that strikes me as getting into the realms of the "Spirit World" and Shaman territory.
The Spirit world and the Physical world are obviously two separate things.
The way I flavor my world setting, that is simply different from the "Natural World." Mages don't really understand how Druid magic works but still believe themselves and their magic to be superior...Clerics don't really care how it works, but know it's not from the Gods, ergo Druids are heathens...or worse.
Well, that's how I see it anyway.