Allow me to propose a theory. Then, I will tell you why I have reached this conclusion. I was born before the Second Vatican Council, so I have witnessed the pendulum swing in the Catholic Church from the far right to the far left, and now, back to the far right again. The middle, of course, is best, so I thank God that I have lived most of my life more or less between the extremes, but I am also distressed at some of the things that I see among young devout Catholics. Naturally, every new generation rebels against its elders to find its own cultural niche.
Millennials, however, are so varied that it seems as if they are groping for identity. Both the worldly and the faithful defy the style of their elders, but they seem to lack the same creativity. Both secular and devout millennials often borrow from the Dark and Middle Ages because they lack the ingenuity to produce new forms of art. For instance, some Catholic millennials have complained about the music of Marty Haugen and David Hass, but instead of composing something better, they prefer Latin chant. 
I was a professional guitarist, among the first to play at “Folk Masses” in the 60s, and now I play bass in an excellent ensemble that is geared more for songs than chant, yet lately, we even play the latter. I can assure you that Haugen and Haas are superb composers based on objective elements, regardless of one’s subjective tastes. They should be greatly honored for adding beauty to the Liturgy and raising the hearts of worshipers for decades, so I am stung when I hear their work disparaged.
We seem to be in another Dark Age, like the one that followed the Fall of the Roman Empire, because many faithful millennials, like monks in their scriptoria, are busy restoring and preserving the classics instead of moving progressively forward by the Holy Spirit while their secular counterparts increasingly resemble Gothic tribes.
My grandparents may have been upset to see the Tridentine Mass replaced by the one approved by Pope Paul VI, but my peers rejoiced to be able to pray in English and to be engaged by the priest to participate. As a seminarian in the 1980s, I was only given a semester tutorial in Latin, so even now as a priest, I can hardly pray in Latin. Trent emphasized the transcendent majesty of the Most High whereas Vatican II recalled the fact that Jesus is our intimate Friend.
Unfortunately after Vatican II, priests often disregarded Canon Law and proper rubrics, so many conservatives overly reacted by blaming the inspired Council Fathers. This spurred schismatic tendencies, such as the Lefebvrites. Because Pope Pius X had condemned Modernism, he became the patron of disenchanted Catholics who were fed up with priests ad-libbing Eucharistic Prayers and personalizing the Mass in their own image. Going from that extreme to the other, my younger brethren have recently brought back the archaic Dominican Rite.
Certainly today, there is nothing wrong with a twenty-five year old woman coming to church with a veil on her head or her boyfriend receiving Communion on the tongue instead of his hand. 
Reverence is a virtue, but when they kneel for Communion or forbid girls to serve as acolytes, then they pretend to be more Catholic than the Church. Cardinal Archbishop Donald Wuerl of Washington wrote against those who genuflect or kneel before Communion when the norm is to stand because they only draw attention to themselves and distract the congregation.
Our Dominican priory in Washington D.C. was built in 1961. Our chapel was adorned with an elaborate mosaic of the life of Saint Dominic behind the tabernacle done in a vibrant and colorful style. The same form of art enhanced two side altars dedicated to Saints Peter Martyr and John of Cologne. Due to renovations required by the removal of asbestos, however, these modern mosaics were covered and replaced with old-fashioned paintings and a Crucifix. The result is comparatively pallid and stagnant.
Meanwhile, as devout Catholic millennials find refuge in things Gregorian and medieval, their worldly peers increasingly adopt tribal features. Should we be surprised that a Goth subculture has arisen? Of course, the Church does not condemn tattoos, piercings and spiked purple hair, for “In the dubious things, liberty,” but it does defend the integrity of the human body and respects the Creator. Because such permanent alterations of the flesh have now become conventional, did this movement make it easier for society to ignore the natural law? Are these young people trespassing on the role of the Creator? Has the Goth subculture made sex-changes seem possible and acceptable?
In the Age of Discovery, Christian missionaries found half-dressed savages, with tattoos and piercings, and civilized them. Now, their work is decried by secular millennials who emulate the “Noble Savage.” In the same vein, they attack Christopher Columbus who helped to Christianize the western hemisphere as if he was a conquistador. In the name of the god called Diversity, they give equal status to all religions. Reality and illusion, truth and falsehood, goodness and evil are all thrown into their lukewarm stew of mediocrity. “Whatever” is the motto of secular millennials, who are also fascinated by the Dark and Middle Ages, but for them, these are merely settings for cable series with lots of sex and violence. The lack of creativity in this generation is also manifest by countless sequels of films.
Meanwhile, devout Catholic millennials are busy building figurative ramparts and moats to keep the barbarians away. They fill their lungs with incense and watch young priests donning amices in long liturgies that increasing resemble Eastern Orthodoxy. Ironically, the great minds of the Middle Ages broke out of the Dark Ages and made great progress. Hopefully, millennial medievalists will do likewise.
