Planar Shepherds are examples of druids with a diametrically opposed view to this interpretation, who see the Outer Planes not only as natural, but meant to be brought into contact as much as possible with the Inner Worlds.
They're protecting the Material Plane from becoming absorbed into the other planes. This could easily be done via isolationism, genocide, deicide, diplomacy, demagoguery, wards, contracts, banishments or many other approaches. Pretty sure whether they take a Good, Evil, Lawful, or Chaotic approach to it is going to depend on the individual druid and what part of the society they're in, but in the end, they're environmentalists trying to preserve what they see as the unique ecology of the Prime Material.
Not really anything to do with an alignment, natively.
Also, trying to save your soul, but this is true of religious followers of the gods too, who simply have a different definition of salvation. (Varying from eternal happiness, to eternal preservation of your knowledge and memories, to the near-complete destruction of the individual.)
