(journaled Jan 6, 2016)
It certainly is a reminder to us that we are only a part of creation and that we are to be united with the rest of creation in the basic purpose of our creation: praising, magnifying, blessing, worshipping our Creator. Maybe it's partly our smugness, even pride, about being "a special creation," or "the pinnacle of creation," or the "only thinking/reasoning creatures" or whatever. Maybe we don't want to admit that God enjoys and is praised by the rest of creation too, each in its own way.
Scripture is actually pretty anthropomorphic about the ways it does that! Like mountains skipping and stars singing, and so on. Maybe we don't want to be humble enough to realize our position in creation isn't as exalted as we'd like to think. We are IN creation, rather than ABOVE creation, for the most part, aren't we?
Yes, our "special relationship" with God is special. But we are still created beings and we also have a very practical and real "relationship" in so many ways with the rest of creation, to which we are intimately connected, and which we literally depend upon for our very breath and life. We are "animals" in that sense--and too often, in our behavior and attitudes and such, we have to admit that we act like "lower beasts" despite our potential "special relationship" with our Creator.
I guess maybe people are also nervous about getting "off the straight and narrow" and getting caught up in "New Age" or "metaphysics" or "paganism/ druidism/ animistic" beliefs held by those who try to be more closely connected to "Mother Earth." Maybe recognizing that all of creation praises God is seen as being on the edge of a slippery slope. But nonetheless, it is scriptural. And God clearly sees all His creation is "very good" and appreciates His connection to it and its connection to, and praise of Him, its Creator.