The Gloria was not originally composed for the Mass, but by as early as the sixth century, it was used on Sundays and feast days. Since it is a song, it should, of course, be sung, not recited. However, if another song has already been sung for the entrance or if another is to be sung as a responsorial psalm, there is not much point to reciting the Gloria. It is a nice song, but certainly not essential. And if it distracts from the theme of the day's Eucharist, it should be dropped, Good music helps make good liturgies.
Bad music guarantees bad liturgies.
Of these problems, the most common is probably the incompetent amateur for the simple reason that most pastors are too cheap to pay for good music. The Catholic Church, unlike the black Baptist churches, simply does not have a tradition of community singing. And until Vatican II our best choirs were more likely to be trained in Gregorian chant than in vernacular songs. Luckily we were able to steal a number of good Protestant songs, but it will take decades for us to develop songs and talent of the quality and quantity necessary for weekly Sunday liturgies. In the meantime, patience will be needed by both musicians and congregations.