In the 8th and 9th centuries, the Eastern Church went through the trauma of Iconoclasm — which literally means the breaking of the icons. At issue was the place of icons — the depiction of Christ and His saints — in worship and in the Church. The Iconoclasts equated their use with idolatry. The Seventh Ecumencial Council convened in the year 787 at Nicea specifically to defend icons and their use from a theological point of view. This view eventually won the day and icons are used by Orthodox Christians in worship to this day; however, underlying the whole controversy was humanity's relationship with nature and the place of nature in the Kingdom of Heaven.
The Iconoclasts had a difficult time with the depiction of Christ and His saints because they saw the act of making an icon to be an insult — that to use mere matter to depict our Saviour and the Holy people of God was to denigrate them. This argument finally runs counter to and calls into question the Incarnation of Christ — God Himself took on our humanity (became "mere" matter) for our salvation. It also fails to understand our place in creation and our relationship to creation. During the Seventh Ecumenical Council, St. Leontios of Cyprus states:
Through heaven and earth and sea, through wood and stone, through all creation visible and invisible, I offer veneration to the Creator and Master and Maker of all things. For the creation does not venerate the Maker directly and by itself, but it is through me that the heavens declare the glory of God, through me the moon worships God, through me the stars glorify Him, through me the waters and showers of rain, the dews and all creation, venerate God and give Him glory.
This sacramental view of our relationship can be seen in 1Peter 2:9:
You are a chosen generation, a royal priesthood, a holy nation, His own special people, that you may proclaim the praises of Him who called you out of the darkness into His marvelous light.
In other words, our stewardship of nature — and the proper orientation of environmentalism — is centered on God. Through us — our prayers, our sacramental life and our "reduction of our carbon footprint" — nature is lifted up to God and participates in the eternity of the Kingdom of Heaven. In a very real sense, the proper platform from which to understand environmentalism is Christianity.
Thus, from this perspective, I believe that the LBBs got it right when they listed the Druid as a monster. As a defender of nature, the Druid fails to unite humanity with nature. Instead, they choose nature over and against civilization. They have no qualms about murdering thousands if it means saving a fish.
In my own understanding of the Lawful/Neutral/Chaotic alignment rules, I like the illustration of the city being attacked by hoards of cthuloid monsters and their minions. If you are on the wall defending the city, you are Lawful. If you are trying to break down the gate, you are Chaotic. If you don't care either way, you are neutral. Using this illustration, Druids actually fall closer to Chaotic than they do Neutral. Civilization is the major threat to nature and must be opposed. In this sense, Rangers, as the class that learns the ways of the wilderness in order to protect civilization from the wilderness, are the natural foes of Druids, not their comrades in arms, as they are in later editions of D&D.
Ultimately, the Druid's defense of nature makes the same mistake the Iconoclasts did in reverse — nature and humanity are incompatible. The result is destructive — the Iconoclasts destroyed thousands of invaluable religious artifacts and killed those who defended them, and Druids are willing to murder and destroy in the name of nature. In contrast, the relationship of humanity to nature in Christian theology is creative. We are called to not only protect our environment, but to live with it and to transform it — lift it into the Kingdom of Heaven to the glory of God.
In contrast, Druids are frightening. In my own version of the Temple of Elemental Evil, Druids run the show. They are rightly called monsters, and in my own worlds and campaigns they remain so.