Well, I don't know anything about this gentleman. What I do know is this: I'm an Episcopalian in an Anglo-Catholic parish, and I sing bass in the choir. I recently attended a funeral mass for one of my wife's uncles. This was (as far as I can tell, not being a Catholic) a complete mass, with the Liturgy of the Word and a Eucharist.
And I found just about all the hymns unsingable. I'm pretty good at sight reading, but the tunes are more like something you'd hear from a lounge singer at a bar than in a church. I did notice quite quickly that I was the only person present who was even trying to sing them; apparently Catholics have given up on hymns, content (or resigned) to listening to the musician do so.
I thought one of the concepts of the Novus Ordo mass was to enable the congregation to participate in it. Where the music is concerned, this has failed.
Depends on the Parish. In my Parish, and the two neighboring Parishes I sometimes frequent, the hymns and musical settings for the Mass are almost always singable and orthodox, and often quite old. In my former Parish, in a different diocese, the hymns were typically unsingable semi-pelagian dreck.
Our whole parish sings with the choir. So please don't put all Catholics in the "non-singers" category. It merely speaks to the poor job the music minister is doing in those parishes in getting people to sing!