Laws that make it illegal to discriminate would not help businesses (they lose the ability to use every signal available to them, and it might become taboo to ask about why one is unemployed, etc), and it will probably result in more discrimination lawsuits from disgruntled interviewees. No one needs more of those.
That said, the stance of some of the companies in the article is silly.
That said, the stance of some of the companies in the article is silly.