It has been theorized that OF&F was intended to arm favored cartels.
They could have just shipped the darned things directly, or laundered them through intermediaries. Why involve the potential security leaks, such as disgruntled agents and gun store proprietors? Why risk having them turn up on home soil at crime scenes?
At the very best, I assume incompetence and hubris. At worst, this was a very badly mishandled scheme to inflate false statistics.