First of all, no public policy (even following the writer's lead that MMM is trying to effect a change in society/policy) applies to 100% of the intended parties. People don't sign up (intended parties omitted), and people cheat (unintended parties participate). Every social program has flaws and inefficiencies in design and implementation. So the use of "nobody", "everybody", "none", "never", "always", and such absolutes are invalid based on past experience with policy.
Furthermore, society includes people of all ages at all levels of maturity, education, and occupation. While one group of people is enjoying the fruits of financial freedom, there will be another group who is still working in preparation for their own period of freedom yet to come. And another group is still in school getting ready to start their own period of work. And the cycle continues.
Society is a system, and systems evolve. Neighborhoods near a new tech campus will see housing prices escalate as the market attracts newcomers with increased salaries. As online sales increased, brick-and-mortar stores began to adapt or face bankruptcy. When the model for households moved from single-earner families to dual-earner families, several economic factors changed. There will always be consumption--both of necessity and choice. Once society has tasted the sugary sweetness of discretionary consumption, a diet of widespread financial frugality is as unlikely as a widespread diet of the gastronomic variety. The resulting problems of poor financial choices will no more cause the masses to change direction than bad outcomes from poor food choices cause the masses to change their lifestyle of high intake and low output.
So while the masses continue to make their poor choices, I'll make better ones. No policy change will overcome the lack of financial momentum by the masses without sacrificing the increasing momentum of the motivated few.
