The thing about seeking rent, is that's domain names are not a limited resource, even .COM. Domain squatters are seeking rent, but not in a traditional sense of a limited amount of land.
A creative individual can come up with a new, memorable name. If you have a service about pets, then pets.com doesn't have to be your name.
For example, a friend really wanted [firstname][lastname].com, but there happened to be a hugely popular singer with this name, so he went with 1[firstname].com, resulting in a short, catchy registration.
In terms of land, you can't just create it (and in terms of reclaiming land from the sea for example, that land is considered capital).
Sure, there are a nearly unbounded number of .com domain names, but there absolutely is a limited number of memorable, reasonable length domain names in .com, which is what I and everyone else are referring to when we talk about this problem. If there wasn't, you wouldn't have domain squatting.
One's target audience generally has a harder time picking up and remembering completely made up names.
A creative individual can come up with a new, memorable name. If you have a service about pets, then pets.com doesn't have to be your name.
For example, a friend really wanted [firstname][lastname].com, but there happened to be a hugely popular singer with this name, so he went with 1[firstname].com, resulting in a short, catchy registration.
In terms of land, you can't just create it (and in terms of reclaiming land from the sea for example, that land is considered capital).