So, firstly, it was kinda broken ...
You could unlock warehouses without having iron-sticks, and then you're stuck, and the feel of iron sticks always felt bad
We also decided to rebalance things for our mod's 1.0.0 release, since it's pretty stable now
Lore wise:
Warehouses need some sort of shelving to support the many many items stored, so think of the chests that are used to create the shelving for all the items (and gives you an excuse to automate iron chests).
As for the extra concrete and advanced circuits used in the logistics versions, there's got to be at last a smoother floor for the logistics stuff to happen better inside the warehouses as well as the electronic goodies inside the warehouse to run.
That being said .. why are iron chests a bad choice for this and what would you add (considering iron sticks may not be unlocked)?