The shortfall is what I call a form of Tax that is levied without full disclosure and in an atmosphere of hype and misinformation.
Only from a averaged, numerical view.
I'm not even getting into psychological effects of hope...just from the mere mathematical hope, it can be worth it.
For example, suppose you havef very low income and low earning capabilities. If you put a dollar a week into an account, or invested it in a pretty nicely yielding investment of some other kind, you would likely still not have enough to pull out of poverty. While the return might make things easier, you might find that the difference it made was far less enticing than the chance at getting out of that situation.