How often do you have a conversation with someone about a technical issue and they persuade a group of people to follow a particular course of action just through force of personality and several quickly thrown out numbers?
This describes that situation exactly. Most good ‘arguers’ are good because of they way they present the material. Not because they are right.
All the more reason for engineers to have good rhetoric and writing skills. Your opinions, no matter how well founded, are basically useless unless you can successfully convince people. I do agree, though, that in the end of the day it should matter more who has the best engineering rational than the most skill in arguing.