I'd like to think that right now, we cant comprehend why and what the zombie virus is. I kinda see it like being the Black Plague of our times- It cuts down 2/3 of us because we are not mentally equipped to understand it, just like those 14th century people couldn't comprehend why was that happening to them. Lets not forget that they had their own theories- The church thought that its because people were sinful and adulterous (real original there, Church), and the Paris university concluded that it was caused by harmful fogs coming from the southern oceans. The Fogs themselves were caused by a bad planet alignment.
So yeah, for me the point of a zombie virus would be to make us open our minds to new possibilities. What if human apathy causes the virus, or anger? What if some formulation of ''being a dick'' generates the whole thing? You know kinda like Dr. Masaru Emoto's studies (the guy that researched water molecules in contact with different human emotion), only not pseudoscience, but actual real truth.

TL;DR The Virus should give us the opportunity to learn something new about ourselves, and let us correct our view of life.

Of course, if we just do what the Black death people do, we will simply survive it and learn the truth centuries later