I do see the sense in that, but at the same time, it seems like a weird division. If some artist makes a recording using high-quality samples in such a way that it sounds like they could have recorded their piano or whatever other instruments they're using, and I wasn't aware of the origin of the piece, I'd probably credit them as "performer: instruments" (especially if they had someone else in a clearly demarcated role, say vocals). With that format, though, if I later dug deeper and discovered that they had never actually touched a key and did all the work with their mouse, I'd then wind up removing the relationship entirely rather than narrowing it down as I would if they had stuck a microphone in a true grand piano. Could just be my love of consistency protesting, though.
That's what I was thinking, but I wanted to be sure that that role hadn't picked up any other connotations beyond that description.
EDIT: Well, I've found one argument for using "performer": Picard doesn't download the "programmer" credits. Not sure if that's big enough to affect things, but it is something.