The Orlando shooter was a nutjob. Yes, ISIS took credit, understandably, but their actual involvement is questionable. It is as likely that he was a homophobic and/or in the proverbial closet, considering that he was known in there.
The fact is that this nutjob, as so many other nutjobs on shooting sprees in the US, could legally obtain their weapons. How many of these tragedies could have been avoided simply by making them just a tiny little bit harder to obtain?
The number homicides per 100,000 population in France in 2012 was 0.21. It was 3.43 in the US in 2014. Of course it's a gun problem.