Criticizing an article serves no purpose unless you're the
  editor or publisher. Since you're not Gwenol* Buck - and the
  issue of gun deaths as well as the issue of mental illness has
  been brought up, talk about them or rewrite the article. Either
  way is productive. "This article sucks and here's why" says
  nothing to further discussion.   I don't like the bad
  correlation either. I agree. I also found other things; while
  the headline says "mass shootings" a number of examples were
  kids killing parents. Is that a mass shooting?

  I'd even go so far as to say the article is poorly written.

  Conclusions invalid. I could shred the whole thing apart.

  But regardless of the bad correlation, which _is_ worth pointing
  out and you are correct about that, do you think that mental
  illness, being a contributing factor in killings, is a subject
  worthy of discussion?