He probably could, but it's probably best not to do so. It is good to be "discerning" about what we listen to, and to evaluate individual performers, but it can get a bit scary to identify individuals as "willing to sell their soul to the devil."
Now, if you want to identify particular performer's *songs*, or things they've said, or ways they've behaved, that's another thing. If you want to critique the different ways that Sandi Patty and Amy Grant have behaved in light of their marital unfaithfulness, vs. the way that Michael English did, that seems all right to me. If you want to critique the heretica song "Above All" that Michael W. Smith sings, that's probably fine.
But it's dangerous to say that someone's "selling their soul to the devil"....