1. Because the majority does not possess the means of survival by subsistence and are forced to cooperate with proprietors.

2. "Property" cannot exist without enforcement. If you own land and I don't, chances are that I can find another poor bastard who will help me to take it from you.

I just want to note first that it is not clear that all land is currently owned. Natural owners (homesteaders) have been displaced many times by state violence and the threat of state violence keeps people from homesteading available space. I had sidestepped this earlier because, even if all land has legitimate private owners, that does not preclude voluntary cooperation.

1. Your body is your property, and you have the right to contract (i.e. agree with another person to use your property in a particular way, for instance as a condition of transfer of property). So the filthy rich person who owns a country--which by the way I don't think is possible, since he probably just planted a flag and yelled that he owns it, which does not make a homestead... but for the sake of argument let's say he does own the country--this guy excludes thousands of people who only have the standing room on which they were born. Do tell me how this guy will eat. I will bet that, through the magic of self interest, the landowner will be happy to contract with the impoverished majority, say, for farming. Now if you're thinking ahead, you already see that the poor folk, if their private property rights are respected, can save their income and trade and sell among themselves, maybe even buy some of that land from the country owner. The historic problem is not that ownership of land existed, but that it was never treated as a private property, or that the individual right to self-ownership and contract were not universally respected.

2. So people can be crooks? I don't disagree.