I'm not sure, but when I was dating the woman who would become my wife, she not only insisted on me seeing it, I also had to accompany her and a group of her girlfriends. I was the only male in the theater, and I clearly remember listening to the agonized sobs that permeated the air as the credits rolled. No one moved for about 5 minutes, and the "crew" spent dinner analyzing the film.
Oh, well. It was a serviceable, albeit predictable film. I have never watched it since - but my younger brother was subjected to the same relationship test when he was dating the girl who became his wife.
I imagine these kind of things are just expressions of "If you love me, you will show in an interest in things I love" - which is alright in my book even if the thing she loved was a textbook example of a sappy romantic movie.
By the by - Nicholas Sparks has made a lucrative career off of the tears of his readers, so maybe we should all blame him.