"When asked to explain in their own words the main reason for leaving the Catholic Church, about half cite a disagreement with the church's religious or moral beliefs. For those now unaffiliated, about half were unhappy about birth control, 56 percent about teachings on abortion and homosexuality, and 40 percent about the treatment of women."Yep, those are the 3 issues where Catholic doctrine most prominently differs from the "anything goes" mentality pushed by secular modern culture. While a number of the mainline Protestant denominations have chosen to abandon the traditional Biblical teachings on these issues in the name of "modernization", the Vatican has thus far resisted the pressure to do so.
As St. Paul preached to the Galatians almost 2,000 years ago:
"For do I now persuade men, or God? or do I seek to please men? for if I yet pleased men, I should not be the servant of Christ. But I certify you, brethren, that the gospel which was preached of me is not after man. For I neither received it of man, neither was I taught it, but by the revelation of Jesus Christ." (Galatians 1:10-12)The CSM article mentions in passing the fact that most people who switch affiliation do so prior to the age of 24, but the Pew Forum website goes into more detail. Nearly half (48%) leave Catholicism prior to the age of 18. An additional 30% leave between 18 and 23.
To me, this statistic shows the failure of families, parish CCD programs, and Catholic schools to properly catechize Catholic youth as to the reasoning behind Catholic doctrine. I've discussed this issue at length here and here. If we want young Catholics to "follow the narrow way" and resist the siren song of moral relativism, we need to do more than simply tell them the rules. Catholics of whatever age are far more likely to obey if they understand *WHY* the Church teaches X, Y, or Z. It's far easier to dismiss simple appeals to clerical authority than it is to dismiss a reasoned argument in support of Church doctrine.