1. Check your tone. Again.
2. Yes, it is a matter of Eywa (in a way, or it might be a certain species of plant that creates natural antibacterials, not sure, likely a bit of both), but no, I would not call it bull****. How do we know Terran darwiniamisn is a universal law? How do we know life on Pandora didn't evolve through cooperation? Or at least some other evolutionary mechanic than is present on Earth? Or maybe Eywa was initially a product of darwiniamisn, but that changed when she achieved consciousness? Just thinking out loud, here.
Again, it's all speculation at the moment, we can only wait for JC to put the next canonical material out for something definitive. Rest assured, though, I'm sure it will be fairly scientific. JC called in scientists to help create a believable world the first time around, I'm sure he'll do it again. Obviously they'll be some artistic license, but JC likes his projects to have science as a major cornerstone.

