However, returning to Burkus, my experience is that maturity is lacking in most organisations to allow total transparency about salary.
I find that those who are very capable underplay their contribution/worth - probably as they have the breadth of vision and the confidence to be frank about all the stuff they don't know/do.
The difficulty is usually amongst those with less ability. Their lack of breadth of vision and lack of self awareness leads them to foster an inflated view of their worth/contribution/career prospects.
Feed that into salary transparency and the result is a lot of management time soaked up attempting to counter the needs of fragile egos.