Comparing two cities of drastically-different sizes and cultures hardly makes a case. If the commentator really wanted to, he should have gone where most others, particularly those on "our side" do, to Florida. Of course, he makes no statement regarding how many Flint murders were committed by people who have gone through the process of becoming licensed/permitted to carry a concealed firearm.
There could be many reasons why Flint has an increased crime rate. One could be that the economy in that state has been so unstable as of late.
This isn't an "article"; it's a "commentary", and, as such, it lacks any hint of any kind of research or education on the subject.