What's the rationale? "If your manager does not value what you are doing then quit your manager" would make more sense, but of course would be of little practic

What's the rationale? "If your manager does not value what you are doing then quit your manager" would make more sense, but of course would be of little practical value. For the record, you are not employed by nor for your manager. Have a look at your employment contract, it is probably not written that your job is to please or help promote your manager. Usually, your job is to perform some kind of action directed towards the outside of the company (like shipping software to customers). That's really my issue with big companies: by the sheer effect of inflated volume, one gets surrounded more and more by coworkers, internal projects, etc, and come to forget that the purpose of it all is to act on the outside world not within the corporation itself. That's at least how I understood the parent's "think only about doing your job" and I agree wholeheartedly.