Ever since the Greenspan Commission raised payroll taxes in 1983, the government has used the SS surplus to fund general expenditures. To suggest people aren't paying their fair share for social programs (or any other fed expend) is historically inaccurate if you focus solely on income taxes versus ALL federal taxes. Now, in another couple years, you might have a case....
It's not much different than claiming the wealthy pay most taxes. Why did Willie Sutton rob banks?