It is essential that someone in your company thinks from the perspective of a customer. The author of this article/post is suggesting that that person's title

It is essential that someone in your company thinks from the perspective of a customer. The author of this article/post is suggesting that that person's title is "Product Manager" (although they wear different hats). He is NOT suggesting AFAICT, that you dump financial resources into a do-nothing "manager" as you are implying. I've heard time and time again that you NEED product management in a startup. Think of a new name if you find the title misleading.