The first thing I would point out is that this is really no different than a mosque or a buddhist temple, etc. It's base idolatry, it just so happens that they're attempting to do so on public land.
Secondly, I would point out Isaiah 44 (emphasis added):
Isa 44:8 Fear not, nor be afraid; have I not told you from of old and declared it? And you are my witnesses! Is there a God besides me? There is no Rock; I know not any."
Isa 44:9 All who fashion idols are nothing, and the things they delight in do not profit. Their witnesses neither see nor know, that they may be put to shame.
Isa 44:10 Who fashions a god or casts an idol that is profitable for nothing?
Isa 44:11 Behold, all his companions shall be put to shame, and the craftsmen are only human. Let them all assemble, let them stand forth. They shall be terrified; they shall be put to shame together.
Isa 44:12 The ironsmith takes a cutting tool and works it over the coals. He fashions it with hammers and works it with his strong arm. He becomes hungry, and his strength fails; he drinks no water and is faint.
Isa 44:13 The carpenter stretches a line; he marks it out with a pencil. He shapes it with planes and marks it with a compass. He shapes it into the figure of a man, with the beauty of a man, to dwell in a house.
Isa 44:14 He cuts down cedars, or he chooses a cypress tree or an oak and lets it grow strong among the trees of the forest. He plants a cedar and the rain nourishes it.
Isa 44:15 Then it becomes fuel for a man. He takes a part of it and warms himself; he kindles a fire and bakes bread. Also he makes a god and worships it; he makes it an idol and falls down before it.
Isa 44:16 Half of it he burns in the fire. Over the half he eats meat; he roasts it and is satisfied. Also he warms himself and says, "Aha, I am warm, I have seen the fire!"
Isa 44:17 And the rest of it he makes into a god, his idol, and falls down to it and worships it. He prays to it and says, "Deliver me, for you are my god!"
Isa 44:18 They know not, nor do they discern, for he has shut their eyes, so that they cannot see, and their hearts, so that they cannot understand.
Isa 44:19 No one considers, nor is there knowledge or discernment to say, "Half of it I burned in the fire; I also baked bread on its coals; I roasted meat and have eaten. And shall I make the rest of it an abomination? Shall I fall down before a block of wood?"
At the end of the day these people are going to cut metal and/or wood and fashion a false god out of it. This would be no different than carving a table and worshiping it. It's not going to save them. It's more saddening than anything.