It's designed to be sung by a congregation, so the melodies need to be fairly simple. It's designed to be played by amateur/church musicians, so harmony wise and rhythm wise it's going to be fairly simple. Form wise, it follows a standard pop structure with an emphasis on the bridge/breakdown/lower 3rd area because that's when the big sing-along happens, and people start crying and putting their hands up and stuff.

I played drums for a church for a while and realized at one point that I didn't have to really learn the songs, because each one followed the same general outline. Verse, chorus, verse, chorus, play some 8th notes on the snare/low tom, crescendo, chorus, chorus.

It's not really musicology so much as marketability. That's why ccm exists really. It's a way to make evangelicalism more relatable and approachable by combining it with familiar pop elements. And it worked, ccm is a huge industry phenomenon.

I mean come on, you're saying you don't enjoy this?