I'm not sure the scandal is responsible for the loss of the "nons" - that only broke about 2002 with much of it hitting the news around 2008 - the loss of the parental generation and 20 somethings occurred before.
It is not only the Catholic Church that is losing outright membership - Protestant churches are faring even worse.  
I think there are many factors are contributing to this phenomenon.  The increase in all things secular - even the loss of the "Blue Laws" - certainly took away from the focus of going to Church. The increase in having both parents working outside the home, the subsequent decrease of doing things together as "family" - even eating meals together, the increase of sports on Sunday morning, the laws & rules against mentioning God in school (including changing "Christmas vacation" to "winter recess"and "Easter break" to "spring recess") in the hopes that everyone would not be offended....& much more, but running out of characters :-) has led to demphasis on God.