Architecture students bristle when Joshua Prince-Ramus tells them that they are entering a rhetorical profession.
A great architect isn't one who draws good plans. A great architect gets great buildings built.
Now, of course, the same thing is true for just about any professional. A doctor has to persuade the patient to live well and take the right actions. A scientist must not only get funded but she also has to persuade her public that her work is well structured and useful.
It's not enough that you're right. It matters if it gets built.