@Nullo Main part of my point. The thing blatantly ignored in the article are all the other factors that go into a planet’s habitability, such as an iron core to create a strong magnetic field to deflect the suns most harmful rays (upon further research I realize that as a larger planet it is more likely to have this, but the fact that this was ignored was still bothersome), a moon of larger than usual size relative to the planet to control tides and absorb meteor impacts, gas giants to protect from the bulk of meteor impacts, a tilted axis to regulate the seasons, and placement among the less star-dense areas of space, which is the real clincher – obviously most of the stars are concentrated in the densest part of galaxies, right? So where are we? Right at the edge of one of the Milky Way’s arms, where the star concentration is far less dense. That’s why such ideas as 1 in 5–10 stars having a habitable planet orbiting them is the most ridiculous thing I’ve ever heard. As you get nearer and nearer to the core of the galaxy or even the center of an arm, radiation and other factors become unbearable.
According to the article, however, the scientist only claimed that 1 in 5–10 could have a planet in the habitable zone; it’s unclear whether the more rash statement that all these planets would then be habitable is to be attributed to the journalist or the scientist, but I guess I’ll give the scientist the benefit of the doubt.
All in all though, I have to assume they’re either terribly misinformed (which would be sad indeed) or simply trying to get more people interested in the field (for purposes of funding) through slightly untrue measures.