Just like my point in the previous post, people who are in debt still pay into FICA without complaint. Why is this any different?
Because this separation of savings and debt is counter-productive to your ultimate goal, which seems to be forced financial responsibility.It's almost always better to pay off debt before contributing to savings, aside from maybe having an emergency fund. Forcing people to contribute to savings while ignoring any debt that they may have, while at the same time removing a large amount of most people's ability to reduce that debt, is not responsible. It's the exact opposite.
Instead, I think you should decide on an income level people require to survive - enough to pay rent, utilities, food, etc. Then, a minimum percentage of pre-tax income above that (I would keep it at 10% to be honest) is exempted from tax and transferred to this savings scheme. This has the advantage of not treating adults like children, it has the advantage of giving people the ability to exercise some financial responsibility of their own while mandating responsibility over some of their disposable income, and it provides an incentive, by reducing tax paid, to save more.
EDIT: realised I didn't really answer your question. The reason this
should be different is because you're trying to improve it. It's counter-intuitive to try revise something and yet not fix any of the problems of the previous revision.