I'm not against 401K programs per se, but I think a lot of people are really uneducated and misled about how they work; many people are told fantastical stories about "free money" and "the magic of compounding" and "set it and forget it" and all those other bromides, without noticing the "free money" gets eaten by fees, the magic of compounding is at the whim of the stock market, and if the markets ever tank, that money is gone forever.
That million dollars your 401K administrator is promising you is also an unattainable fantasy unless you can really weather a huge amount of risk. After all, investment is risking the money you earn on the stock market, and the messages to "save more" are really "put more risk into your investment account."
401K pre-tax contributions have been a boon to investors, as it has long reduced taxable income, and it would be more damaging if the government told employers that the matching contributions they made would be taxed as ordinary income. That "free money," in the eyes of the government, is still earned income, and thus taxable income.
Two things would happen if the government taxes matching contributions: employers would severely reduce or eliminate them, as it would affect the employee's taxable income, and employees would reduce or stop 401K contributions, as they would no longer receive that added benefit.
Hence a retirement account loses all meaning; it is now a socialized investment vehicle that the government can raid at will and the contributor has no say in funding. Couple that with government-approved funds and bonds that satisfy only wonks, activists and control freaks, and you might as well call it a supplemental Social Security fund.