The Joyce Foundation, the same assholes who bankroll the Brady Campaign, are pretty well known in the pro-rights community for providing funding to almost anybody who will push their anti-rights agenda. The Buckeye Firearms Association has a nice writeup about the Joyce Foundation using money to get journalists to write anti-gun stories.
I’m not one who subscribes to the idea that journalists should be unbiased but I do feel perfectly fine with pointing out potential reasons for bias. There is a huge incentive for a journalist to write anti-gun stories if a large foundation is willing to float them Federal Reserve notes for doing it. This tactic is often used to get desired results from studies; somebody gives a bunch of researchers money, express to those researchers the preferred bias, and then has them set out to get a study that proves that preferred bias. You can prove anything if you twist the numbers enough which is evident when anti-gunners reveals their numbers of people killed by guns each year but only mention in the very tiny print that a huge chunk of those deaths were suicides (which are self-inflicted deaths and therefore really can’t be counted when talking about gun violence).
Needless to say the Joyce Foundation has been throwing money at anybody willing to do research that shows a bias against guns so the findings in the linked article aren’t at all surprising.