I wonder about the nature of the sample for this survey. The author of the study is LCMS, and the LCMS (Lutheran Church Missouri Synod) is extremely exclusive and fundamentalist...
I'm sure if you surveyed say the student body of say Bob Jones University in SC, you'd find similar results, which really doesn't tell you much. There would be no market for Christian rock if such statistics were accurate among broadly evangelical teens. It's a huge market too.
Christian rock may be nice and certain groups may embrace it, but it doesnt mean they want to hear durring church.