Personally I think I've gone a bit deeper in this topic, because I also think that if taxes were public, people with the same job but different tax situation will have a different bargaining position, meaning salaries will be affected by the actual tax rates people pay.
I'm also interested in the visible effects of wealth and income regarding wages: do people with some money in the bank earn more money in general? (would it thus mean that the best investment is to get some cash first ?) etc.
For the more emotional argument, wouldn't public wages also prevent people with lower incomes giving money to higher incomes? Something that happens often is many human relationships where wealth can be hidden? Wouldn't you tip higher to the waitress you know is gaining well below what you think she would, and wouldn you demand more of your boss if you knew exactly how much more they made?
I'm not going to say its strictly better for everyone to have the information public, but I can rarely fathom believing that hiding information leads to better decisions. And isn't that what its all about. At this moment all these objections are a sort of growing pain, not objections for the long term.
The "market solution" only awards to the best negotiators.