That's a very frustrating article. It takes an interesting story (new forms of life being discovered in strange places) and tries to make it sensational (shadow things exist all around us). Regardless of which atoms are involved, if a creature takes up space, it will show up under a microscope. The article makes it sound like there are invisible things out there, not just small, but undetectable. Considering the billions of blood samples and tissue samples and soil samples that have been looked at over the years, to say that we haven't looked is absurd. Unless you start talking about gaseous entities or paranormal vapors ... ugh.
The important point of the article is that we're now able to look in more difficult places, and I'm glad to see that strange things keep turning up.
I agree that "alien" is overused. These things are certainly exotic. It would be interesting to find out when "alien" began to be used for extraterrestrials -- long before that it was used to denote foreigners, and sure, ETs are the ultimate foreigners. But the word is thrown around like candy now.
The bulk of the article is well done, with lots of good ideas. It's just a shame that they had to pander to the looney tunes. It certainly doesn't mean that every paranoid fantasy monster is suddenly real.