I think the issue is that a "free" market is a theoretical construct and not a practical one. There is a lot of asymmetry in contract negotiation and without these sorts of laws you get what we have in America, which is many people wanting more vacation time but having difficulty getting it (even software engineers who are very in demand right now will complain of not having enough vacation sometimes). From talking to Europeans I think most of them would agree that these laws make their life better and a law that makes their citizens life better pretty much across the board doesn't really seem to be huge overreach
The 19% of youth in Europe who are unemployed don't have any of the cushy legally mandated benefits of employment there, and might be happy to forego a few to be employed at all.
It varies a lot by country. Maybe I might have a little of a skewed view because I've talked to people mostly from Germany and The Netherlands, which both manage to have have decent labor laws and fairly low youth unemployment.
