That word (‘rapid’) matters a great deal if you’re talking to stakeholders or management in many an Enterprise organization. Because without it, any “prototyping” work will be shot down in flames the instant the term is mentioned. These folks have a reflexive, assumptive association with prototyping: that it’s slow, cumbersome and expensive. So while I agree that our industry has a ridiculous love affair with buzzwords, I do think the distinction matters in the context of selling its value to large organizations.
Excellent food for thought here, regardless ;-)