So right now I'm the pianist for a little ensemble of guitars and singers that plays at Mass once a week. After having been in GIA territory for the past 5 years, I now find myself in OCP land and don't know pretty much any of the "contemporary" songs. Occasionally there is a song that is scheduled for the upcoming weekend, and I glance at it, and it looks a little difficult, so I decide to run through it and "learn" it in advance. 100% of the time, I sit down at the piano, and play through it, and find myself not only able to sight-read it, but immediately find it boring-ly predictable.
My point of this isn't that it is a reflection on my own musical abilities, but rather, the lack of any sort of musical-sophistication contained in the music geared for contemporary groups.
Now, if I have no difficulty running straight through it since it's so predictable, then it does seem to follow that it would almost as easy for the average congregation to be able to pick it up.
But whether that is a good thing or not, is another conversation...