Very different approaches, but both coming from the feeling you quickly get that you can not be truly free if you're surrounded by fenced off land once you're used to it.
The other effect is that there is - ironically in a country with extremely high government ownership of other things - less pressure in the government to own land.
We don't need national parks (we still have some) to make land accessible to the public, because it all is.
It would also be very expensive for me if someone hurt themselves and then sued me since they are on my property.
I’m going to get downvoted for this but Europe is relatively community minded and frankly a little naive. The US is hardcore when it comes to individualism and will frankly exploit everything up to the very edge of the law. You would have tours of private lands set up within the week especially if you have anything interesting on there. My last point is that Europe is a relatively small place so there isn’t a lot of land to roam but the US isn’t like that. There is plenty of public land to roam so we don’t really need this law.
Put succinctly I would simply say that there are fewer degenerates. One bus or subway journey in NY and one in Stockholm is enough to see that.