The justification for private property is that the market would force it to be used somewhat optimally. Modern financial instruments and zoning regulation have

The justification for private property is that the market would force it to be used somewhat optimally. Modern financial instruments and zoning regulation have distorted this to the degree that real estate can be extremely irrational for decades and often people just go without many services (such as housing) due to this. I'm generally pro private property but at least from the perspective of someone living in the US I sometimes question the idea when it comes to real estate in developed areas.