Adjusting to two weeks of vacation/sick leave was a challenge when I immigrated to the US. After five years with my current employer I now get four weeks.
It's a symptom of the belief that "you should feel lucky to have a job" - you should be grateful to have two weeks of leave, not expect more like most other OECD country. I am also constantly amazed at how many coworkers don't use the small amount of leave they get.
It'll be interesting to see if changes in employment patterns will eventually push the US towards a mandated number of vacation hours.
It's not a symptom of the belief that you should feel lucky to have a job. We're talking about the same country where people who go to college expect jobs to be handed to them.
Instead, it's a complex cause rooted in a country built on entrepreneurship and a strong belief in the "free market" (whatever that means). This is why it's not regulated by any government (federal, state, or local). The US has a lot of factors that lead to its vacation policy, but, "You should feel lucky to have a job" is not one of them--that sentiment is a more recent attitude.
I am also constantly amazed at how many coworkers don't use the small amount of leave they get.
Perhaps two weeks of vacation is standard because many Americans want additional money more than they want additional vacation.
You know, it's even possible that many people from other OECD nations would prefer more money and less vacation - they just don't have the option to make that tradeoff.
Worth noting that this is a fairly uniquely American standard and would be illegal in most of Europe.