Sure, but in another 50 years many of their children will have just as much land through none of their own doing. If others could have used the land better, I'd say there's a good deal of unfairness there. It's possible life could have been better for everyone if not for inheritance.
>Blasting music is a different story - you are effecting your neighbour's quality of life (and destroying his property value).
Eh? That's the sort of thing I was talking about. You have the right to do what you want, within reason. But that said, you can't for example use residential land for a commercial enterprise beyond a certain point, and there are good reasons for these sorts of zoning laws.
On your last point, the state is the proxy by which we as a group determine how to divvy up that wealth that cannot be directly attributable to any one group. Again it is imperfect, but it's better than letting those who own the land have the entire say, because they are not necessarily responsible for the value in that land.