I can't figure out what kind of a program people think it is. Democrats call it an insurance program. However, insurance does not pay back everyone who pays in. It pays those who have claims, only. Imagine how much your car insurance would go up, if the companies had to refund every old person everything they paid over their lifetimes when they stopped driving. Pretty silly, right?
We don't sit around trying to figure out how to get back the money we have paid on homeowners' insurance. I think most people are glad not to have claims. If people could get sane in this way we could means test beneficiaries and everyone else could be grateful not to be in their situation. Middle class entitlements is something that is unafforable.
You're rght, it's not an insurance program. It's a mandatory retirement program. As such, participants expect their 'pension' when they retire.