So your question becomes "why should property rights exist in the first place?"
The answer is that our existence, by nature of being a human being, has material requirements. Humans have non-material requirements as well (friendships, hobbies, art etc.), but you can't dismiss the material requirements of the human experience. The same reason that it needs to be your food, your bed, your clothing is the reason that land ownership needs to be a protected right as well. If you weaken respect and protection for land ownership then, rationally, you weaken the recognition of all property rights from food to clothing to musical instruments to your tech devices. Each material "property" may serve different purposes for the owner, but that doesn't negate the necessity of owning property. And a claim to property is the ability to control its use.