Second, market forces keep the cost of owning a home below the cost of renting a home (in most markets).
Third, there are substantial legal and financial benefits to owning at least your primary residence. Home sales are usually free of all capital gains tax; mortgage interest and property tax are tax deductible; and homestead exemptions exist in many states in the case of bankruptcy.
Finally, there are only so many other places to put your money. It is difficult for an employee of a corporation making in the low six figures (i.e. for a typical reader of this website) to shelter more than around $30,000 of earnings a year from taxation. Because of the advantages listed above, once you max out your retirement accounts and have an emergency fund set up, there is often no better investment than the purchase of a primary home. Also note that paying down your mortgage early is equivalent to investing your money in a savings account that earns a rate of interest equal to the rate of interest on the note (at this point, this rate is much higher than the rate you can earn in a savings account). This is on top of all of the other benefits.