For instance, a janitor could be very thorough, but very slow. Is this a good or bad thing? Well... it depends on the circumstance. And this issue with circumstance is that most things are circumstantial.

Great example! Thanks for providing it. I feel I've got the solution for this as well, albeit perhaps poorly explained. So, due to the breakdown of the positive attributes (cleanliness, promptness, attentive, hygiene, etc --> all attributes that go along with being a janitor), we can also rank particular jobs on their exhibition of those attributes. I've definitely done a poor job explaining this.

Suffice it to say that, all else equal, the faster job would be more "valuable" than the slower job. Great point that will certainly have to be addressed in more detail!