What are some of the reasons why Catholics would feel more drawn to focus on pious devotions than the Psalms?
As phrased this question is somewhat opinion based, but I would see some merit in answering it. The recitation of the psalms has never been an obligation.
To state that ”the Rosary is said to have come from a tradition that did not allow the laity to focus on the 150 Psalms,” is completely bogus.
Let us start by going down memory lane.
The early Desert Fathers recited all 150 psalms every day.
St. Benedict in his Rule makes it clear the his monks are to recite the complete psalter every week. Yet even St. Benedict allows monks who are unable to read to be allowed to replace this recitation with something else at the abbot’s discretion when they cannot make it to choir.
Even in the Early Church, the faithful chanted the psalms together.
All these presume that one is able to read.
The history of the Rosary may indeed surprise you!
Before going on with this part, I just want to let you know the earliest versions of the Hail Mary was purely based on the Scriptures!
Hail Mary, full of grace, the Lord is with you. Blessed are you amongst women and blessed is the fruit of your womb Jesus. (Luke 1:28, 1:41-42)
The last part of the Hail Mary was added during the Black Plague. That is right, the Black Plague.
This second part (“Holy Mary, Mother of God, pray for us sinners now, and at the hour of our death”) is believed by many to have been added during the plague to ask for the Blessed Mother’s protection from the fatal disease.
Venerable Fulton J. Sheen explains this origin in his book The World’s First Love.
Since it seizes upon the two decisive moments of life: “now” and “at the hour of our death,” it suggests the spontaneous outcry of people in a great calamity. The Black Death, which ravaged all Europe and wiped out one-third of its population, prompted the faithful to cry out to the Mother of Our Lord to protect them at a time when the present moment and death were almost one.
How the Black Plague changed the “Hail Mary” prayer
The Rosary, just like the recitation of the Psalms are both devotional practices within the Church. When you state that “it seems to me that most Catholic lay people do not focus on the 150 Psalms (found in the Bible) in their daily prayer life,” you have no way of knowing that. Both of these devotions are very well encouraged in the Church. The Rosary does have the advantage of being easily memorized.
Now, a little history of the Rosary, some of which may surprise you.
Knotted prayer ropes were used in early Christianity; the Desert Fathers are said to have created the first such, using knots to keep track of the number of times they said the Jesus prayer or the 150 psalms.
According to pious tradition, the concept of the Rosary was given to Dominic of Osma in an apparition of the Blessed Virgin Mary during the year 1214 in the church of Prouille, though in fact it was known from the ninth century in various forms. This Marian apparition received the title of Our Lady of the Rosary.
According to Herbert Thurston, it is certain that in the course of the twelfth century and before the birth of Dominic, the practice of reciting the Ave Maria 50 or 150 times had become generally familiar. According to 20th century editions of the Catholic Encyclopedia, the story of Dominic's devotion to the Rosary and supposed apparition of Our Lady of the Rosary does not appear in any documents of the Catholic Church or the Order of Preachers (Dominicans) prior to the writings of the Dominican Alanus de Rupe (also Alan de la Roche), some 250 years after Dominic. However, recent scholarship by Donald H. Calloway seeks to refute this claim.
Leonard Foley said that although Mary's giving the Rosary to Dominic is recognized as a legend, the development of this prayer form owes much to the Order of Preachers.
The practice of meditation during the praying of the Hail Mary is attributed to Dominic of Prussia (1382–1460), a Carthusian monk who termed it "Life of Jesus Rosary". The German monk from Trier added a sentence to each of the 50 Hail Marys, using quotes from scripture (which at that time followed the name "Jesus," before the intercessory ending was added during the Counter-Reformation). In 1569, the papal bull Consueverunt Romani Pontifices by the Dominican Pope Pius V officially established the devotion to the Rosary in the Catholic Church.
From the 16th to the early 20th century, the structure of the Rosary remained essentially unchanged. There were 15 mysteries, one for each of the 15 decades. According to John Henry Newman, Mariology is always Christocentric. During the 20th century, the addition of the Fatima Prayer to the end of each decade became common. There were no other changes until 2002, when John Paul II suggested the five optional Luminous Mysteries; variations of these had previously been proposed by George Preca, and were implemented during the mid-20th century by figures such as Patrick Peyton. - Rosaryu
Even in the end, when you say that ”it seems to me that most Catholic lay people do not focus on the 150 Psalms (found in the Bible) in their daily prayer life,” it may not be entirely true. It seems you might be asking the wrong Catholics! Many of us lay Catholics read the psalms. Many monks who recite the psalms say the Rosary also!
So what are some of the reasons why Catholics would feel more drawn to focus on pious devotions than the Psalms?
It is an easy form of prayer to follow.
It allows Marian Catholics to express their devotion to Mary the Mother of Jesus.
It is calming when stressed out with human affairs.
It is so easy to take a Rosary with you all the time, even hiking and camping!
Devotion to the Rosary is a special sign of predestination