Plus, this strategy generally works best for first-time buyers. People who already have a home usually need to sell it in order to buy their next one. If a "move-up" buyer wants to buy a home during a depressed market, that means they usually have to sell one during the slow market, too. If a seller wants to sell his home to take advantage of a "hot" market when prices are fairly high, they generally have to buy their next home during that same hot market.
It tends to equal out.
Finally, the business cycle can change over time. Since 1983, we have had two fairly long expansions with only a slight recession in between each. You would not want to wait nine years to buy a home, would you? You could miss out on a substantial amount of appreciation by waiting, and end up paying much higher prices.