There is a very recent article by Bishop Olmsted of Phoenix that supports your statement. This wonderful article can be found here:
catholicsun.org/bishop/2011/121511.html
From the section called “What is sacred music?” :
“Sacred music is distinct from the broader category of what we may call ‘religious’ music, that which aids and supports Christian faith but is not primarily a part of the sacred liturgy. ‘Religious’ music includes various devotional music, such as much popular hymnody, ‘praise and worship’ music, as well as a host of other musical forms.”
Later, he quotes Pope Pius XII on “religious music”:
“…it can exercise great and salutary force and power on the souls of the faithful, both when it is used in churches during NON-LITURGICAL services and ceremonies, or when it is used OUTSIDE churches at various solemnities and celebrations.” (Musicae Sacrae Disciplina, #36)
Personally, I think that the misuse of this type of music (by using it in the Mass) has come about, at least partly, by the huge drop in non-liturgical devotions at parishes. In most places,there is no venue for this sort of music outside of Mass.