But even for the poor working stiff, I think your analysis is mistaken: an employee pays 100% of SS and MC taxes whether he wants to believe it or not. He also pays 100% of his "paid" vacation, 100% of his "paid" leave, 100% of his "employer" contribution to health care ... and so on and so on.
The truth is that an employer fully accounts for every penny of an employee's expenses, and that includes all contribution supposedly made on his behalf; that's the meaning of "fully loaded" wages and benefits, and that's how an employer budgets you (I know this because I've been on that side of the equation, too.) Believe me, no employer budgets employees on the basis of gross wages. That's one of the reasons idiots continue to back Social Security: they think they're getting one over on the boss by "forcing" him to pay 7%+. They aren't. They're paying it.