Earlier quoted context omitted.
The last thing anyone wants is efficient markets in labor. It would make unions illegal, for example, as the entire raison d'etre of unions is to use market power to raise prices in a coordinated manner. So let's not start pushing for "market efficiency" arguments because those will really come back to bite the proponents of this bill.
An individual may not want efficient markets for their short term interest. A society most certainly benefits from efficient markets in the long term by properly allocating labor resources. The bottom income/wealth deciles should definitely welcome price transparency, unless they are "temporarily" embarrassed members of the upper income/wealth deciles.
Efficient markets assume an infinite amount of indistinguishable goods sold by an infinite amount of producers with only marginal costs. This theory is useful because in many situations (e.g. commodities markets) this is a reasonable approximation. That is very different from how labor markets work, even in theory. Labor is not a commodity, there are heavy fixed costs (the costs of skill acquisition), and search costs dominate labor markets.