Mark, Ian, Tom, others,
As to the word "profitable" has anyone ever made more money on renovations than new course designs? Major, 18 hole renovations can be pretty big fees, which I guess is the point of some comments here. But of course, hard to talk most courses into it anyway, because, well, ya know, spending less usually beats spending more!
Master plans are typically, IMHO, break even, in hopes you get some consulting work every year. As often as not, the clubs take the MP and do it in house with the supers, etc. The whole spending less thing has them consider avoiding architects at nearly all costs.
As to the other comments, yes, every renovation, maybe every feature on every hole of every renovation, is a separate case and a value judgement. The easiest call to make is the 20-20 hindsight one, where no one knows what the gca was tasked to do, or why. Sometimes, its obvious, like the road widening at SFGC. Most times, its not.