Yes I think you are right that many Protestants would be surprised at how much scripture is read in Catholic (and Anglican Churches) during the church year. Just because they do not see them toting their bibles to church they assume that liturgical types don’t read scripture. What I would say is that our evangelical (non liturgical) brethern in general know scripture better in terms of memorization (which they do in things like AWANA from preschool age) and can list the books of the bible in order.
In terms of why some Catholics leave the church I can give a partial explanation. Many Catholics (not all) attend service by coming late and leaving right after swallowing communion. It is sad but a phenomen I witnessed in several Catholic churches I have attended. On the other hand when you go to a Southern Baptist Church for instance there is a sense of involvement in the service (most people singing), warmth, coffee and fellowship after service, Bible studies for all ages (multiple adult groups to fit any style and age group), activities throughout the week for children and adults, parenting programs, etc, etc. In other words your Christian life became a major part of your life outside of the 1 hour on Sunday. The closest I came to this environment among Catholics was when I was in the military and they had adult bible study on Sunday and fellowship after service, etc just like Protestants. The community was dynamic, fun and alive.
I think if the Catholic church were to conquer this area they would achieve much and stop inroads being made into Catholicsm here and in the South American Countries by Protestants. It is not just Catholics as here in the US many Episcopal Churches are in the same boat. It would take a major cultural shift but it CAN happen. One of the largest Catholic Churches in this area has done this. They attract people from all over the city, are dynamic, active and amazing (every bit as much as any large Southern Baptist Church). The people in the church made the culture shift and have one blessed active community from children to seniors. It is amazing to be in a large youth mass and see 67 year olds holding their hands over someone to pray for them.
Catholics need to get exited about their faith (not just defensive but downright joyous and excited about the gift they have to offer).
Rev North