Look up the journalist online. You'll find that he's considered the founder of a certain school/style of journalism. I think that's sufficient credentials, but if you want, look up his publication history, which you will note contains not a single Kindle book or self-publication. Look up his educational history, which you will note include no self-schooling or non-standard, non-accredited education. You know, do something besides sit there in your armchair to contribute to this discussion.

Anyone can get anything published if they self-publish. That is not the same as having articles published in peer-reviewed publications, such as the Atlantic or the New Yorker, or newspapers. In the latter such environments, someone actually reads your work and judges whether it is worth being printed. Often, you won't be considered for publication without a history of being published by other similar organizations, and certainly not if you've put something out yourself on your rinky-dinky website or through Amazon epubs. Comparing Kindle authors to published journalists is like comparing kindergartners to people in grad school, because they're "both students." One of these sets actually knows what they're talking about, while the other...Well, Johnny might not be able to count to 100 just yet, we're not sure, but we're confident he'll get there by the end of the year!

Meanwhile, Foos isn't trying to claim to be a journalist, he's claiming to be a scientist. That involves, also, peer-reviewed studies, acceptance by the scientific community, basic shit like I don't know, following the scientific method, etc.

Attempting to trade on an "he could have been published, IF [but wasn't" is a very cheap argument, btw, fwiw. I could argue "IF" all day, but at the end of it, the fact is that "if" is a theoretical, not an actual, and therefore almost unilaterally inadmissible as an argument strategy:

  "If humans had wings, we would need to be careful about how close we got to the sun."
  "Yes, but we don't, so your comment is irrelevant." 

You don't want there to be a distinction, so you're refusing to see it. That's fine. But it makes this discussion pointless.