Two things here.
One, go figure, crashes increase while flight hours decrease. Wonder when they'll figure out if they increase flight hours for us, crashes just might decrease.
Two, its a given that single engine aircraft crash when the engine fails. When they designed these aircraft, and took into account the initial aircraft cost and life cycle maintenance costs, they new up front that losing a projected XX number of single engine aircraft to engine failure was still cheaper than putting in two engines. One serious reason why JSF is single engine even though all of us would prefer two.