I attended a Catholic elementary school for grades 1-7 (1965-1972); I started at the tail end of Vatican II, which ended in December 1965.
I have to say I learned more about the faith in the first 2-3 years of religion classes than in the remainder of the time I was in Catholic school. When you consider the level of material presented at that grade level (by necessity), that's a pretty sad statement. In the upper grades we spent far more time making felt banners, learning folk songs, and being fed pop-psychology (though I didn't realize it to be such at the time) than learning theology. The theology we were taught was not very true to the faith.
To be clear, the problem wasn't Vatican II itself, but rather the post-Vatican II fall-out -- most of which had nothing at all to do with what actually happened at the council. Certain factions took advantage of the council to introduce all sorts of nonsense of their own contrivance into both the liturgy, religious education, and even clerical and religious formation.
I think because their hearts haven't been touched by God, because their hearts are closed by various reasons.
Being baptized doesn't automatically make you a great Catholic.
Going to church doesn't make you a great Catholic.
Following the ten commandments doesn't necessary make you a great Catholic.
The secularism isn't something which brings you to faith.
God reaches always out - in good or bad things which He allows to happen; we have to take that hand of His and let your heart get touched. Out from that we need to come to a personal relationship with Christ and then "we" want to know more about the beauty and richness of our Catholicism and of our Holy Church.
St. Benedict talked about "conversion of the heart" as necessary for the spitirual life--and he referred to his monks when he taught this! He also said (in Latin of Course) "The cowl does not make the monk."
Fortunately his teachings became dispersed to us the laity--along with works by Thomas Akempis and Thomas Acquinas (who wrote the Summa Theologica for beginners--hard to believe but that's what he wrote). All of those writers talked about this conversion and how it is not given, but sought and (on some level) earned in phases after the hard work of seeking.
Conversion of the heart is a discipline and many of us (whether we go to Church or not) are undisciplined. Many or us either fall away or go through the motions after we become confirmed--and our spiritual maturity stopps at that point.
I have seen how Catechesis has evolved from when I was in 1st grade. Even when I was growing up, CCD wasn't taken very seriously by any of us or by our parents who viewed CCD (the way we view schools today as well) as catechetical microwave ovens where they put kids in, turn the machine on, and they are supposed to come out years later with the knowledge of Thomas Acquinas, the dilligence of St. Benedict, the courage of St. Ignatius of Loyola, and the sense of charity of St. Francis. Without parental participation, teachers feel their efforts as futile. Some parents aren't even active in the Faith, so why would their children be? along with this is the fact that CCD kept changing it's curriculum where I lived. Believe it or not, I was confirmed with only a scant and passive knowledge of Our Lady, the value of confession, and appreciation for His Presence in the Eucharist. I would go to Sunday school sometimes with the idea that most of the program was a hastily thrown together way of presenting the faith. This is unfortunate today.
The long short of it is that our culture is undisciplined in just about every aspect (let's call it like it is). That said, most people would be afraid of the rigor required of Conversion of the Heart. This discipline is my responsibility and I think more people should talk with our parish priests more on this subject--unless of course they were afraid that they would have to change themselves and their life (Heaven Forbid!!) When discussing the faith with some of these people, and they ask me a question I do not know, I refer them to the priest (who is a local expert and treasure trove). Not many have taken the recommendation.
this is nothing new. read homilies written throughout the ages and you will see the same lament. i had to learn it on my own through reading. later i found opus dei where i was given a great spiritual and doctrinal formation. as a kid my religious education ended around 1971, when a sort of values clarification replaced doctrinal instruction. a generation later. the tide is turning. trust god - peter's boat will never sink. do your part to spread the faith. i taught RCIA then ran adult education classes on various topics. after a few yeas away from that, i just joined my parish's evangelization committee.
While being Catholic used to really mean something in terms of what you did and what was required, it has been largely lost and being Catholic is more of a cultural identification than really a faith. For many at least. That plus poor catechesis (think of CCD!), the decrease in religious teaching in our Catholic schools), to the "feel good" style of homilies of priests educated as part of Vatican II, etc. Family support waned, with their own lack of education on these points, and lack of time, lack of care for spiritual formation, etc.
You have to pretty much do it on your own...there are parishes to be found that are orthodox and will feed you what is needed, reading, EWTN, groups, prayer, but it is largely something you have to do on your own, and most people are not motivated enough.