You are implicitly assuming that the shareholder primacy theory of corporate governance is the only legitimate one. It is not. The business judgement rule allows corporate directors very wide latitude in how they choose to run the business. Google very much can hire more CSRs, exactly because they are insanely profitable on a per employee basis, but they choose not to, for reasons unknown, but likely out of concern for the stock price.

See https://en.wikipedia.org/wiki/Business_judgment_rule