Since this is where you dump the dirty litter, it tends to get fairly messy and I like the ability to remove and fully sanitize this portion, making the locker a better design. One final reason, and probably the most important to me, is that the litter locker makes it much easier to use garbage bags instead of the refills sold in store.
https://www.amazon.com/Litter-Genie-Plus-Pail-Silver/dp/B007IRMTXE

