Ohhh, no its not. There are parthenogenic species of lizards and snakes that can reproduce completely without males. As in, in a genus of lizards, there are no males in the population. Have never been males, will never create males. Females, while not having male gonads or anything, will actually mount each other and act like males, which somehow stimulates their reproductive organs better. Basically, going lesbo is the only way for them to continue on reproducing. Apparently it comes from some weird hybridization between two other lizard species that creates this totally parthenogenic one... cool stuff.
And I would highly debate that reproduction is the sole meaning of life. I could possibly agree with that just in the animal world, but I definitely think that with humans, this is no longer the ultimate meaning of a life.