John Adams, in his letters to Thomas Jefferson, wrote of a "natural aristocracy." That even in a society that treated its population equally, certain men are going to advance beyond others. That theory is applicable to personal finances as well.
You can see two guys working the same job for the same salary. One works to save for the future, the other is working to pay off credit card debt after buying crap he didn't need. This second guy is type that will bemoan how difficult it is to save, not the first guy.
It comes down to what one considers "necessities" in life. Living within one's means. Etc. It doesn't require being financially astute, or even smart ... just practical.
It's a skill many, if not a huge majority, of Americans no longer possess. I bought my home with cash. I have no credit card debt. No debt whatsoever. However, the car I drive is a 19 year-old wreck. lol. I don't have cable TV. I cut my own grass, and don't see a need to have Mexicans do that for me. I don't even have a cellphone.
And this discipline applies outside of personal finances too; whether you eat or drink too much of the wrong thing, smoke, etc. There are always going to be those who live for today, and those who squirrel away their nuts for the winter.
Is this the fault of the existence of the 401K, or is it just human nature? Obviously the latter.