The General Introduction of the Roman Missal assigns the reading of the intentions of the Universal Prayer (Prayer of the Faithful) to the deacon. Articles 71 and 94 clarify that other people can also read the intentions, but the deacon is the first choice. I do not know how this is administered in the US, but here in Austria, you will not often find deacons reading the intentions.
First of all: There are not many deacons here. Most parishes do not know what to do when such a rare specimen shows up. The intentions are commonly read by other people – men, women (one of the few opportunities where women have a chance to speak publicly in a Roman Catholic Mass), or kids (quite often this is one of their first appearances on a public stage).
Secondly: Many deacons prefer to leave the intentions to laypeople. The deacon has enough to do in the Mass anyway, so why should he disappoint others by taking that role from them? This has to do with respect for laypeople’s commitment to liturgy.
Thirdly: Many deacons do not know that reading the intentions is their job.
The question is obvious: Why are the intentions appointed to the deacon?
As far as I can see, every Universal Prayer in the fourth and fifth centuries – when solemn public liturgy evolved in the Roman Empire – was led by deacons; except for the concluding prayer which has always been appointed to the bishop or priest. In Eastern liturgies, singing the intentions is still one of the deacons’ major jobs. That is why the ability to sing is one of the most important skills a candidate for deaconry should have. (You can listen to a beautiful example here.)
But this only shifts the question into ancient times: Why are the intentions assigned to the deacon?
One of the main aspects of deaconry is that the deacon is meant to be sort of “Secretary of Social Affairs”. This might have been forgotten for a long time. But after the Second Vatican Council – reintroducing the permanent deaconry in Lumen Gentium 29 – the Roman Catholic Church started to adopt this biblical (cf. Acts 6) and ancient tradition. It is the deacon’s mission to take care of people in need. Of course, this is every Christian’s mission, but deaconry makes it a visible, public, personalized ministry, representing Christ as the servant of the people (the “deacon of all”, as Marc 9:35 says in Greek).
What is the meaning of the Universal Prayer? Confiding people in need to God.
The deacon takes care of people in need in everyday life. Consistently it is his job to remind the others of people in need during the liturgical gathering. How does he do that? By reading the intentions of the Universal Prayer! The deacon, as the Secretary of Social Affairs, is the personalized link between what Christians do in liturgy and what Christians do (or should do) in everyday life.
I understand why laypeople love to read the intentions. But we should leave them to the deacon. His ministry has a very serious meaning: It is the link between liturgy and charity.
While we talk so much about priest shortage, we should realize that our deacon shortage is even bigger – so big that parishioners do not even miss anything in a deacon-less liturgy.