I don't know, but my guess is that fire suppression systems are supposed to protect people and may not be required in storage buildings?
It depends on what the building codes say in the locality whether fire suppression systems are required, but regulations don't prohibit their installation. Sometimes insurance companies will dictate installation, as it affects the risk they're taking and would likely reduce the premium if not required but installed. I'm sure the owner regrets not spending the $2-3 per square foot that a sprinkler system costs for new construction.
Moral of the story - if you're storing something valuable and/or irreplaceable, spend a bit of money up front for fire protection.
