If the government has a very big disk, then let's fill that very big disk with tons of crap.
NSA: "We're at 95% utilization of our storage. We better delete some old stuff so we have room for new data."
-- OR --
NSA: "Hey Congress, encryption usage has skyrocketed! We need more money to buy more storage to save all this encrypted data we're capturing!"
If the government has a very big disk, then let's fill that very big disk with tons of crap.