All of the rhetoric about AR-15s tells me the government KNOWS the people absolutely hate them. They are then very afraid there is going to be a revolution, so they have to figure out a way to keep guns out of the hands of the mob and/or confiscate them and they need to do it quickly. The momentum towards that is really moving fast.
Their concern is very real. They must set up the playing field where the opposition is severly outgunned by the authorities. That is the complete basis for all of this, not random mass shootings.