The market economy is a tool which the more assertive use quite effectively to extract both producer and consumer surplus from the less assertive. The market economy is thus a meritocracy of assertiveness. That it is probably also a meritocracy of other things seems plausible, but this is of little consolation when there are few help wanted ads in fields other than sales or collections. The fact that well over 90% of openings are unadvertised is of little consolation when you don't have a (expletive deleted) "network."
According to the (expletive deleted) economics textbooks, extraction of surplus from producers or consumers is associated with incomplete information, price discrimination and market power (monopoly and monopsony). It seems obvious to me that pure assertiveness can also accomplish this result, quite independently of the competitive or informational condition of an industry. After all, everyone knows that the squeaky wheel gets the grease.