perhaps you missed the customers requests of "clean, simple, and clinical"
also, the visual hierarchy of text is as the customer has requested with Spine & Disc being the most prominent. The box surrounding the text, I feel, ties the smaller text in with the rest of the logo making it feel more unified. the tic-tac-toe you reference is a 3X3 grid meant to represent the 33 human vertebrae. As always, I appreciate everyones input, but constructive criticism is much better received than strings of negative adjectives with no suggestions.
What I think he's saying is that the negative space isn't balanced well in relation to the type. I'd also go with some variance in the face choices and the kerning needs a lot of work. Helvetica is fine it's just not very inspired and you haven't really pushed or balanced it effectively.