In the United States, "The 'C' Word" is particularly offensive to women, in a visceral manner that, IME, goes beyond the use of other slurs used about or towards ethnic, religious, or social groups.
I don't know why. I don't know at what point in the education of a girl or woman they develop value that this one word is unforgivable. All I know is that at one point in my Army career we were discussing a particularly loathed NCO and used the word, and the topic of conversation immediately turned to whether SSG Drang should be beaten to death. (Slight exaggeration.)
This is what comes of serving in a branch with a high percentage of females soldier: I had no idea to that point this attitude existed, and I doubt I would to this day if I had been, say, an 11B. It is also instructive to watch BBC America and see what they can get away with saying on air. (Although I have stopped doing so regularly, since Top Gear ended.)
As atonement for my contribution to the thread drift/digression, here's a pic of my Smiths. I thought I had more of just the Model 10, which is my father's retirement piece, but if so, the internet ate them.