Well, considering that I have been involved in Catholics Returning Home for about 20 years or so, I would say that I am not without some experience with those not attending.
Not once in all of the people I have met through the program have I ever had anyone state they were not attending Mass because of any of the 5 issues listed in the opening post. And that includes being involved in the program in two parishes for awhile.
Issues repeated: 2nd “marriage” after a divorce, without a decree of nullity. Someone who made them royally mad - relative, pastor, nun, parish personnel; it’s amazing how someone who feels seriously hurt by another will take it out on the Church. Going off to college has been another source - away from home, partying, sexual activity, and off they go. Poor catechesis: they never really learned of “got” what it is all about; they saw it as simply a bunch of rules with no integration into their life.
Am I an expert? Nope. But I read a lot, talk with a lot of people, and observe a lot. And it is still my firm opinion that anyone who walks away from the Church over what they say is bland or irreverent Masses has something else at play beneath all of that, if for no other reason than that they are walking away from the Eucharist. In short, there is form over substance. And sorry, I don’t buy that one.
And having been around for 71 years, I know plenty of my relatives, as well as prior classmates who do not attend regularly. Again, not a single one.
One of the causes I have seen repeatedly is what we used to call mixed marriages; coupled with the Catholic who was properly catechized - but they had head knowledge, not a whole-hearted acceptance of what the head knowledge taught. Or, to put it in what used to be a Protestant comment, they did not have a personal relationship with Jesus.
To that we can add secularism, and in particular, the sexual “revolution”. Shacking up with a girlfriend or boyfriend does have a tendency to put a damper on one’s religious fervor.
Presentations and programs have not been flopping out here. The issue is more of how to get younger people to commit to a multi-week program when they have young children.