Insurance rates go up, and Social Security is an insurance. There is a limit on wages (about $110,000) subject to total benefits. 1972 rate was $9,000.00 wages earned per year. 2013 will have a limit of $113,700.
The real problem is the rate of change for the average workers' pay. The average or nominal pay for individuals hasn't advanced as inflation and/or devaluation of the currency they received as payment for work and products that were purchased.
In other words: Work=energy is true in physics and monetary distribution of value. If no energy is used to produce currency then a distribution of wealth is a false.
Social Security was built on a solid foundation. It's the disparage of currency/wealth that skews the system.
It's a basic problem of the American economy.
“To be yourself in a world that is constantly trying to make you something else is the greatest accomplishment.” ---Ralph Waldo Emerson