So I don't know all the motivations behind the 401(k) legislation (I seem to recall that the original plans were using a type of loophole, until the plans were coded into law, but I could be wrong on that). However one thing that it does do is it gets the average middle-class American very interested in the health of the stock market. Typically non-investors would be concerned with jobs, inflation, and interest rates. But by tying everyone's retirement funds to the health of the stock market, that can get people to support governance that makes their retirement fund numbers go up, even if it cuts into jobs or one of the other metrics (ideally people would look at everything in balance, but they tend to look at their 401(k) balance as it exists right now instead of what it will likely be in 10-20 years under alternate policies).
Now since the bulk of stocks are held by the wealthier class, who benefits more with a healthy stock market, the existence of 401(k) is a vehicle to get the broader classes of voters to vote against their best interests if it means making those numbers go up.
Any thoughts on the above? I haven't read any articles or commentary that states it like this but to me it kind of makes a lot of sense.