The caveat to the caveat is that property value doesn't always go up, and there are benefits to not owning your primary residence. If property value goes down, it is better to be a renter, because you just end up with cheaper rent instead of an underwater mortgage, or you can decide to just exit the neighborhood if things get too bad.
That said, property values tend to go up over time. While there are cases of it going down in most places the trend is upward. If you are betting on them going down you are usually going to lose the bet. Renting is usually a bad bet.
That really depends on your local area and your needs. If you decided to keep renting in Vancouver instead of buying in 2002...yeah, you made a mistake. If you decided to keep renting in Detroit instead of buying in 2002 - you have come out quite ahead. Also, even if property values tend to go up over time, that doesn't mean that homeowners can bridge the gap of maintaining ownership in down periods. If you bought in 2006, you might find yourself underwater on your mortgage 3 years later, with stagnating or declining wages and threats of unemployment, and forced to sell, even if you believed the market would rebound eventually.
