If she was an American actress, I might also be tempted to think the same. The formula here for a dying career or empty bank account seems to be a quick T&A shot. But K-CH is not an American actress, and The Vintner's Luck is not an American movie. I don't know much about New Zealand, but in many other countries, nudity in movies is as common as multiple gunshot wounds in American movies. She may have gone nude - not to save a stalling career, but quite simply because it was written in the script; and so she just did it. If you saw Whale Rider, you might remember a bathtub scene. So one could say that K-CH has been doing onscreen nudity since she was 11.
That being said, I thought her nude scenes were tastefully filmed. And she's not hard on the eyes either.