The point is that when our most educated people aren't getting work it discourages people to get more education overall. That's not good. Filling up trade schools with overqualified people isn't going to help the economy or the country overall.
You want the smartest people out exercising their talents in your country, not spraying lawns and fitting pipes - or wandering off to other countries where they are paid for their knowledge.
You could replace the lady in the article with any number of PhDs in hard sciences who can't find jobs right now. I know one personally.