Nothing much -- I just suspect that the level of enthusiasm may have a lot to do with the style of the Sunday service. Perhaps many people of this age can't actually stand going through the same stuff saying the same things every weekend. They may not have the patience but then they feel a religious obligation to make and they think that obligation can be fulfilled by just simply being present at church. As well, there seems to be quite a lot of freedom allowed within the Church and so there is not as much discipline in the people. I guess people need to be firmly guided and given clear and simple rules to go by. Just a bunch of words without active personal follow-up will degrade people's interests in the modern time. Protestants find that in the simplicity of just using the Bible and with, for the most part, much less ritual. Given that there are so many denominations in Protestantism, there is then no center for anyone to look to for something uniform amongst all Protestants. While the scope of this article doesn't allow for consideration of sola scriptura, Protestant worship service and other activities heavily involving the laity are then much more dynamic and flexible so that most members of the congregation really enjoy it. They are able to actively participate in these activities much more readily and are able to keep their minds focused on it because that particular service has grabbed their attention and has seized it. There is nothing wrong with Catholic rites but too many people nowadays lose their attention and internally have little patience to continue to involve themselves in the liturgy by continuing to meditate on the messages constantly being generated in the liturgy.
Actually the Church has always been pretty strict but maybe poor catechetics have resulted in people being very not knowledgeable about their faith. The Popes and bishops down the centuries have always issued letters and things and people are always invited to read them over and discuss about it. People need follow-up as well. The Second Vatican Council stood out to be one of the most important councils ever held in the history of the Church. It made so many significant changes particularly regarding the relationship between the Church and the rest of the world. Not only did it make history but it also became one of the greatest topic of controversy in Christianity. Just to side-step a little bit, maybe it's because of the help of the media that news and opinions surrounding the council were able to spread further and wider thus generating even more reactions. If there were already such things as tv and radio back at the time of the Council of Trent, the picture would have been significantly different. Maybe that Council would have been considered even more important than Vatican. Anyway, the modern times have seen the materialistic and worldly attitudes of people skyrocket like crazy. In the past, we could devote our energies to doing something better because we didn't have nearly as much distractions. Technology has changed all that. We not only have tv and radio, but we also have hi-fi and computers. And then we have the internet where vast amounts of information is transferred and exchanged; far more than the world has ever seen in all those previous centuries. Along with the freedom to seek out and express new ideas comes such attitudes as liberalism and indifferentism. These attitudes, I believe, reflect the selfishness of human nature....you know, "Do whatever you like! Be free to express your personal opinions!" And also, "Let's be open...and treat each other equally!" Man...given the current trends of human morality, such is the misuse and abuse of God-given freedom.
And so there are many "cafeteria Catholics" as well as Catholics ignorant of their faith. People pick and choose what they want to believe. Or people just don't know well enough their beliefs. So when Protestants challenge them, they don't know how to answer and think the Protestants are right. Seeing the energy of their critics and naturally comparing them with the energy level of their fellow Catholics, they think that Protestants must be right. Or else many Catholics not being disciplined or knowledgeable enough about their faith may get attracted into things like psychics or various buddhist-related practices or fung shui (· ¤ô) or some other occult belief. But! The Church may be making a comeback right mow. There is no longer a critical shortage of people entering the priesthood and the Catholic Church in the States seems to be doing better with a new surge of converts from Evangelicalism arising. The Church in Africa and probably elsewhere is doing well too.