Look at the majority of the people who are wealthy in this country and it's through real estate. Even dirt poor farmers are often times wealthy becasue of the worth of their land. Wealth and high income being two entirely different things, of course.
Banks won't happily let you leverage your stock market investments. They won't give you 90% of your investment while letting you put in only 10% (unles you guarentee their 90% with something real). They will gladly take 90%, or more, of the risk of real estate investments, letting you keep the profits on 100% of the value even though you only own 10% of it (if that's what you put down).