I think that is pretty rare.
From what I have seen, women are much more likely to genuinely choose a C-section because they have a career and need to have the baby on a set schedule so they can get back to work. Having a baby the natural way is a fairly messy organic process that does not readily fit into the highly scheduled lives of modern two-career couples.
IIRC, only about 5 percent of babies show up on their actual due date. Most are either early or late. I have read plenty of articles where career women scheduled a C-section so they could schedule the birth and also schedule time off from work. Waiting for a baby to show up when they feel like it is rather inconvenient not only for you, but for your employer if you are anyone of any importance. It can amount to being willing to leave the entire department in a lurch when you suddenly drop everything. Babies can be anywhere from several weeks early to two weeks late, from what I gather. That leaves a window of potentially two to three months in which baby might decide "now's the time." In fact, my understanding is that a baby three weeks early isn't even classified as a preemie. So there is potentially a five week window for a "normal" birth.