Oh hooray, another left-wing political rant on the front page. It's been a few hours since the last one.
If you think not being a wage-slave is left-wing, I think you've been fooled by the people who need you to work yourself to death so they can take it easy.
Edit: Which is me. Forget I mentioned it :)
In fact, my central problem with this article was that ignored the fact that markets in the United States are generally less well-regulated than those in other industrialized nations. Many of the differences the author brings up can be traced back to that. The author clearly would like that changed, but it's a much bigger argument than the one the author is making. It can't be taken for granted that just because these regulations are desirable, and would make things better, then they should be enacted. The Overton window on government intervention in the economy in the US is different than in other industrialized nations, and that needed to be addressed in the author's argument.
Why was that? Could it possibly be because the willing partners in that private agreement aren't as free to choose the terms of their agreement as you seem to think they are? The extra holidays aren't just a line item in the contract, with appropriately reduced pay etc. They are perceived to cause jealousy problems, for one thing. They're also structured as a status perk for long-term employees ("earn a whole extra day for every year of service!" they said).
The issue is even bigger for someone contemplating emigrating to the US, because longer holidays increase the cost effectiveness of transatlantic trip home. Only having 10 days holiday effectively means saying (relatively) permanent goodbye to all your friends and relatives if you also want to have e.g. a Christmas holiday and a summer break.