Think of the gardens and buildings of Temple Square as bubble wrap around that container.
Think of the City Creek Center to the south, the Church Plaza to the east, the Conference Center to the north, and the Family History Library and Church History Museum to the west as a firm, sturdy box around all of it.
When something merits that much protection, you have to figure rough bumps and bounces are coming down the road.
I get a feeling the LDS Church sees turbulence ahead -- nasty weather -- and it is making preparations.
It's not about being defensive and keeping things out.