Easy. Obama hates private gun ownership. The news was flooded with stories about how America was the source of cartel weaponry for about about a year.
Then we forced dealer to complete sales and flood a few thousand weapons down south. That fueled lots of battles and deaths.
They guns were then “traced” back to America, as “proof” that the American 2A was the problem. FBI, CIA, DEA, and AG all played along.
THAT, is the explanation.
The media of course just repeated the lie over and over.
They had to prove it true, somehow.