I'm not too crazy about Trek Lit's interpretation of how the Borg came to be. I have my own idea, I used it in fic. Bottom line is that I think the Borg were a results of technology gone wrong, rather like Harlen Ellison's "I Have No Mouth and I Must Scream."
That's the idea I was getting from Unity. That the mind connecting technology likely started as a wonderful thing, that slowly warped the borg's original culture.