This was a blog discussion. I am only thankful I don't live in that parish. Apart from the dubious theology expressed, it is characteristic of the anti-cultural anti-elitism that is so widespread in Britain.
It is also unfortunately the case that the good settings of the English liturgy done by the Anglican church cannot be used as the words are not the same, so we have had to put up with atrocious and banal settings by certain composers whose names are I expect familiar to you.
I know the names of many liturgical composers, but few whose music I would characterize as atrocious and banal. I know plenty of Anglican liturgical settings which I would describe as over-complex, and in opposition to the true spirit of the liturgy, which is never merely performance.
"Active participation" can mean listening attentively as well as performing. In my experience, most people generally keep silent for hymns, which is why we gave them up - it is the Gregorian chant that people are joining in to sing.
If people keep silent for hymns then that is the fault of the music director who has failed to take seriously enough their teaching duty to ensure the active participation of the community. Certainly 'active participation' can include attentive listening, for example to a cantor singing the verses of a psalm setting, but that too easily transmutes into 'passive attendance' when more than a small proportion of the music used prohibits the community from joining in.
But if you want to give up your job, why not ask around amongst the youngsters who are presumably the people who buy the best selling records of Gregorian Chant and might like to sing it in the church instead of just listening to it on their iPods.
I run music days in the parish several times a year which are attended by large numbers of parishioners, including many young people. I have yet to meet a single one with Gregorian Chant on their iPod, much less one who wants to sing it in church. I have occasionally tried using the Missa De Angelis Gloria setting, or the chant Salve Regina at weekday evening Masses where the profile of the congregation suggests that there might be people familiar with them - I was a choirboy myself in the 1960's and 70's so I'm very familiar with that part of the repertoire. I get one or two people who join in, and a sea of blank faces. Of course if your MD loves chant and assiduously teaches it to the choir and congregation then people can join in with it (unlike polyphony). But I keep my antennae tuned to what people in my parish are saying and I assure you that there's no call for a general return to chant here.
My entire point was that if you don't understand and assent to the theology all you can do is appreciate the music. And that music of great beauty and artistic merit may provide a profound aesthetic experience but actually prove distracting from the religious experience which is the purpose of a church service. Personally I'm a big fan of Durufle's Requiem (sorry, can't find the accent for the final e in his name) as a concert piece.
But I wouldn't want it at my funeral: I'd want my friends and family singing Ernest Sand's 'May the Choirs of Angels' and David Haas' 'You Are Mine' in splendidly untidy unison, because in religious terms the feeling and intention of the praying community means everything and the beauty or otherwise of the performance is a triviality, only of interest to those who don't 'get' what is really going on.