The article itself explains this:

  Privacy is important because it protects you from the influence of others. The more companies know about you, the more power they have over you. If they know you are desperate for money, they will take advantage of your situation and show you ads for abusive payday loans. If they know your race, they may not show you ads for certain exclusive places or services, and you would never know that you were discriminated against. If they know what tempts you, they will design products to keep you hooked, even if that can damage your health, hurt your work, or take time away from your family or from basic needs like sleep. If they know what your fears are, they will use them to lie to you about politics and manipulate you into voting for their preferred candidate. Foreign countries use data about our personalities to polarize us in an effort to undermine public trust and cooperation. The list goes on and on.

There are quite a few stories that have cropped up over the last decade or two that show this is actually happening.... the most precient one I can recall was where Target outted a pregnant teenager to her parents before she even knew she was pregnant:

https://www.businessinsider.com/the-incredible-story-of-how-...