A new Catholic convert who was “struggling” with some things in the faith asked me about the Rosary some years ago:

Mary is most often mentioned in its entirety. I find it difficult meditating on Christ when Mary is so prevalent. Why is Mary so heavily infused into the prayer?

I replied that one must understand the nature of the Rosary and the purpose of the repetition. Most of the words of the Hail Mary are, it should be noted, straight from the Bible. And it's incorrect to say that because “Mary” may be the word repeated more than any other in the Rosary, that, therefore, she is considered more important than Jesus, or the focal point of the Rosary meditation.

The intent of the repetitions of the Hail Mary prayer is to form a sort of “background music,” so to speak, to the meditations on (mostly) the life of Jesus.

It reminds me a bit of an analogy from my past as a trombone player in my high school band and orchestra. We had to play at graduations every year (much to my chagrin), the famous Pomp and Circumstance, by Edward Elgar. Now, was the purpose of the commencement ceremony to hear Pomp and Circumstance 71 times?

No, of course not. It was to honor the graduates for their accomplishment in achieving a high school diploma. The music was the background, just as a soundtrack to a movie is.

It's not a perfect analogy (few are), but the Hail Marys in the Rosary are, at least in part, a sort of rhythmic background to the meditations. It's a way (rather ingenious, when fully understood) to move forward in the prayer, and to avoid distraction: something we are all very familiar with when we try to pray.

Some say it’s difficult to meditate on Christ while repeating the Hail Marys. This is, I would venture to guess, probably mostly a function of the unfamiliarity with the Rosary. It's very different from much of Protestant piety, just as things like penance and purgatory and prayers for the dead or asking saints to pray for us are quite foreign at first to the typical Protestant mind. It's a “learned art.” This experience is common to many converts. Believe me, I know, firsthand!

We find in the Bible a similar sort of repetitious, chant-like form. Take, for example, Psalm 136, where the same phrase: “for his steadfast love endures forever” (RSV) is repeated for 26 straight verses! The Hail Marys in the Rosary are somewhat like that. But they are not “vain repetitions” (Mt 6:7 in KJV; cf. “heap up empty phrases” in RSV; also, Sirach 7:14: “Do not . . . repeat yourself in your prayer.”)

Protestants who argue that all formal prayers that repeat phrases are “empty” or “vain” manage to overlook the entire deeper meaning and import of this biblical narrative, in context. Jesus is recommending and exhorting His hearers to a genuine, humble piety of the heart, as opposed to an empty, shell-like, merely external piety, intended to be seen by men in a spiritually prideful sense.

This theme of authentic vs. sham piety is prevalent in the Sermon on the Mount (see Mt 6:1-6, 16; cf. 7:20-23; 15:9). The same general idea is also observed in Mark 12:38-40 and Luke  20:46-47. It's not that all long prayers are condemned, anymore than repetitious prayers are, but that prayers made with a pretentious, prideful spirit (showing off in front of men; making people think one is “super-pious”) are condemned.

Also, in Matthew 6:7, Jesus qualifies what He is opposing in prayer, with, “as the Gentiles do.” He's not talking about the Hebrew tradition of prayer (which quite obviously included much repetition, such as in the Psalms and priestly chants and prayers). He's not even talking about His frequent target: the Pharisees, but rather, the “pagan” or “heathen” (according to various translations) Romans and Greeks: people who followed a different and ultimately false religion. That element and the aspect of interior piety indicate that the passage is far more than merely a discussion of repetition: let alone all repetition, as if God is condemning that. 

Jesus Himself used repetition in prayer: “he went away and prayed for the third time, saying the same words” (Mt 26:44; cf. Mk 14:39). Worship in heaven is extremely repetitious:

Revelation 4:8 . . . day and night they never cease to sing, “Holy, holy, holy, is the Lord God Almighty, who was and is and is to come!”

We should recall all these things the next time we hear repetitious or formal prayer itself condemned as “vain repetition” or impious.

As alluded to above,  some claim that the Rosary is too centered on Mary. But it's a meditation on the life of Christ. Of the twenty mysteries, only two are primarily about Mary (Assumption and Coronation).

The Apostle’s Creed merely mentions the Virgin Birth (which is more about Christ than Mary). The Our Father [or, Lord’s Prayer], Glory Be, and Fatima Prayer never mention Mary. The Hail Mary is three-quarters explicitly biblical (direct quotation):

Hail Mary, full of grace. The Lord is with thee. [Luke 1:28, spoken by the angel Gabriel] Blessed art thou amongst women, and blessed is the fruit of thy womb, Jesus. [Luke 1:42, spoken by Elizabeth, mother of John the Baptist]

“Full of grace” is a permissible translation of the Greek kecharitomene.

The Hail Holy Queen is directed towards Mary (who prays for us to God), but even it ends (i.e., in the usual follow-up prayer in a Rosary) on a Christocentric note:

O God whose only begotten Son by his life, death, and Resurrection has purchased for us the rewards of eternal life; grant we beseech thee, that . . . we may imitate what they contain and obtain what they promise through the same Christ our Lord. Amen.

Thus, the Rosary is quite Christocentric, as are all Marian devotions and doctrines, rightly understood.