In reading the previous reviews, it struck me that almost none of you people seem to care for Science Fiction. Or, if you do, you've missed the classics upon which this story line was based. So, WARNING!!! If you don't care for the genre, you probably won't enjoy the movie unless it has a lot of special effects, your favorite actor, or some other redeeming factor not inherent in the subject matter.
Please don't misunderstand -- this is NOT a great movie -- but it stands as mediocre, definitely not the worst film ever. If you think there's anything new about the concepts treated with in the plot or the manner in which they were handled, maybe you should try reading Philip Wyley's "The Disappearance" (1974 -- out of print). Kenneth Biller took exactly the same approach, he just change the cause of the obliteration of a gender and had men wiped out instead of women. Even a reread of "On The Beach" by Neville Shute would cause you to rethink your attitude toward this movie, I believe.
If people (of either gender) have no possibility of creating relationships in what we now consider the "normal" manner, they will invariably find some other way to satisfy their needs for personal and social relationships. That does not imply that this movie, either of the books I listed, or I believe that a single-gender society would be superior. It's just a recognition of human nature. In that sense, the tale told in this film is well worth seeing once.