On average, the same amount of money dropped into the NASDAQ will have much better overall returns. Real estate ROI is about 4% per year, where the stock market has held close to 11% over the long haul nearly a century.

For small-time landlords, it's often about "I have a place for me or a family member to live if things go bad". For bigger ones, it's the tax-shelter and the low volitility of real estate, as well as diversity in case you need to sell when their stock is down.