Why does the Catholic Church not celebrate the Feast of Naming of Jesus?
Who says we do not?
Those who follow the Extraordinary Form of the Mass, celebrate it under the title of the Feast of the Circumcision of Our Lord, on January 1st, the Octave Day of Christmas.
Moreover it also celebrates the Feast of the Holy Name of Jesus.
According to the 1962 Missal of St. John XXIII the Extraordinary Form of the Roman Rite, the feast of the Holy Name of Jesus which is kept on the First Sunday in the year; but if this Sunday falls on January 1, 6, or 7, the feast is kept on January 2. - Optional Memorial of the Most Holy Name of Jesus
Those who follow the Ordinary Form of the Mass celebrate it under the title of the Feast of the Holy Name of Jesus, on January 3rd, as an optional memorial.
In both forms of the Mass the exact same Gospel ((Luke 2:21) is proclaimed at Mass. Moreover, the Old Rite only employs only Latin in its sacred liturgy.
The feast of the Holy Name of Jesus has been celebrated in the Roman Catholic Church, at least at local levels, since the end of the fifteenth century. The celebration has been held on different dates, usually in January, because 1 January, eight days after Christmas, commemorates the naming of the child Jesus; as recounted in the Gospel read on that day, "at the end of eight days, when he was circumcised, he was called Jesus, the name given by the angel before he was conceived in the womb." Medieval Catholicism, and many other Christian churches to the present day, therefore celebrated both events as the Feast of the Circumcision of Christ, usually on 1 January. Bernardino of Siena placed great emphasis on the Holy Name, which he associated with the IHS Christogram, and may be responsible for the coupling of the two elements.
In the Latin Rite Catholic Church it is observed as an optional memorial on 3 January by Catholics following the present General Roman Calendar. Franciscans, Carmelites, and Augustinians kept the feast on 14 January; Dominicans on 15 January; in some localities the date was 8 January, in others 31 January, in some localities in Great Britain on 7 August. The Society of Jesus, i.e., the Jesuits, celebrates the Holy Name of Jesus on 3 January as the order's own titular feast. The date of the second Sunday after Epiphany was chosen by the Carthusians, then by Spain. This was the date assigned to the celebration when, on 20 December 1721, it was inserted into the General Calendar of the Roman Rite by Pope Innocent XIII. In the reform of Pope Pius X, enacted by his motu proprio Abhinc duos annos of 23 October 1913, it was moved to the Sunday between 2 and 5 January inclusive, and in years when no such Sunday existed the celebration was observed on 2 January; this is still observed by Catholics following calendars of 1914 to 1962. The reform of the liturgical calendar by the motu proprio Mysterii Paschalis of 14 February 1969 removed the feast "since the imposition of the name of Jesus is already commemorated in the office of the Octave of Christmas." However, the Mass texts of the Holy Name of Jesus were preserved, being placed with the Votive Masses. The celebration was restored to the General Roman Calendar with the 2002 Roman Missal. In Roman Catholicism the month of January is traditionally dedicated to the Holy Name of Jesus. - Feast of the Holy Name of Jesus
The Gospel of all three of the above named masses is taken from Luke 2:21. In fact, it is the shortest Gospel to be proclaimed during the Liturgy of the Word at Mass in both Rites:
“And at the end of eight days, when he was circumcised, he was called Jesus, the name given by the angel before he was conceived in the womb." - Luke 2:21