Well, due to geographic constraints, I:
1) Only applied to, and interviewed at, a smaller number of programs
2) Truly did not like one of them, and the program has had some problems, as well as the institution itself.
3) I liked one of the other ones I'm not ranking but it is simply too far away. I have an ill parent and need to be within driving distance; this program was not, and I was left with no choice.
I felt that at one program I would be truly unhappy and my wife would be as well, so that nixed it right there. Additionally, I felt that I had had a hostile interview with the PD. The other program was great but if my ill parent needs me to be there than it becomes a huge problem having to step on an airplane to get to and fro, and I don't want to have to take off a significant chunk of residency.
I can always reapply, as I have a steady job at the moment that will be around for another year, the question simply becomes am I getting too old?
So while I don't want to be unmatched, I only had six choices to begin with, and if I don't get into that top four, I will obviously be screwed.
As far as not scrambling into one of your choices, that isn't necessarily true. If a program that you ranked doesn't rank you, but has unfilled spots after the match (this happened last year to one of the programs which I am ranking), there is nothing to prevent you from scrambling there. In fact, unless you totally blew your interview, they might be more willing to take you in the scramble as at least something of a "known commodity" compared to a total stranger that they are looking at solely on paper.
My $0.02