That's true. But the article is talking about international flights. So in fact they have way more information in this case, as a passport is required. Granted it might not be the same passport the person arrived with. But it's a passport.

Anyway, I think facial recognition makes sense from a security perspective, as an additional layer of defense. You can make assumptions about what faces you expect to see from the passports that are scheduled to fly. If you see an unknown face in the boarding area, it's reasonable to flag that person for further review.