Crash resistant means things like bond funds that return at a lower rate than most stock funds, but don't drop significantly either. Some specific stock funds tend to run counter (precious metals, for example). Combined with dividend producing stocks, they moderate the effects of market movements. That's why the gross is only about 10% before inflation.
In an aggressive portfolio, I've regularly made 30-45%, but interspersed with some periods of losses. Even with downturns, the market has been very resilient. People tend to lose when they panic and pull money out rather than let it recover...or they foolishly invest in individual stocks that are much more volatile than a fund.