Any sort of comparison of words used in our world with those that may or may not be used in a totally different world based solely on the imagination of those who wrote it is a false debate from the start, imho. One can use our own history as an example in discussion perhaps, but Eorzea is not our past and therefore the comparison is moot. Eorzea is not Renaissance Europe, Medieval Europe, the Shogunate of Japan, or any other time period of our past. It is only vaguely based on real world cultures. Every civilization has had words for what we consider foul language today. They may not be the -same- as we use or may not have really been considered 'foul' perse depending on the culture, but we do not speak Eorzean either. What we do, as RP'ers, is use English, Japanese, French, German, or whatever language may be our medium to -simulate- the language of Eorzea. Which I'm quite confident (considering people are people) has foul language of an equivalent to that which we have today. Or other cultures have had in our past, whatever.
It's fun to discuss, I suppose, but methinks it's also much adieu over nothing