Winsomeness, like attractiveness, is in the eye of the beholder.

[W]insome is an ancient English word that fell out of use until it was revived by eighteenth century Scottish poets such as the aforementioned Robert Burns (Online Etymology Dictionary). Burns was a fierce critic of the Church of Scotland. Consider the thick irony that we are all running about desperately trying to be winsome, ultimately, because an opponent of our Scottish forebears revived the word. For the whole history of the church people have been talking about the goodness of being merciful, just, loving, virtuous, etc. Only in the last generation or two has the emphasis shifted to being this one thing, winsome, and this has only been possible because a critic of the church re-popularized the term in previous generations.