I've yet to read a thoroughgoing sociological analysis of the increase in irreligion among baptized Catholics so I can't really speculate about causes. As ghastly as the revelations have been, they don't seem to have shaken the faith of the committed Catholics I know to the degree I might have expected; those who I know who have left seem to done so over irreconcilable differences with Church doctrine and policy (e.g. gay like me, divorced like my dad, etc.).