A majority of this country has no self control when it comes to saving money and monitoring (or making the tough decisions to improve) their financial situation. 401k, Social Security, even tax refunds are for people who have no control over their own urges to spend money. If you are good at saving money and reducing monthly expenses then invest in buy and hold rental properties. People will always need somewhere to live so your risk is minimal if you know how to buy right.
If you get your pay check and a week later wonder where all the money went then you better have a 401k or you will be dead beat broke come retirement. I think a majority of families don't realize that if they get a tax refund they gave the government an interest free loan throughout the year....what they think is a pay bump come refund time is really money they should have had early on. The problem is families depend on this return because throughout the year they didn't have the motivation to save to begin with. This should not be a safety net but it is for a lot of people.
You can either control your spending habits and lifestyle or you can't. If you can't then you will need a 401k, social security, etc. If you can save money and control your money then you have WAY more options for making a better life for yourself.