More likely, it was simply burnout from this being the fifteenth time, during his administration, he'd given an address to the nation after a mass shooting.
He used these words in his talk to the country:
The shooter was apparently armed with a handgun and a powerful assault rifle. This massacre is therefore a further reminder of how easy it is for someone to get their hands on a weapon that lets them shoot people in a school, or in a house of worship, or a movie theater, or in a nightclub. And we have to decide if that’s the kind of country we want to be.
Then, sort of wistfully, he admitted:
And to actively do nothing is a decision as well.
President Obama knows he's lost to the gun lobby, to the hayseeds who need automatic weapons to dove hunt, to those who think access to bullets designed to mangle human flesh, is guaranteed by the Constitution, crazies and religious zealots like Omar Mateen.