The statistics on genetic involvement in sexual relations is unavoidably harsh. Inbreeding, statistically speaking, is stupid. (Assuming you are educated enough to know about inbreeding.)
I agree: commitment is in the definition of love, isn't it?
However, you do bring up a good point. Girls do want babies. Assuming that good communication is the thing, I'm sure a daughter can have Her cake and eat it too: adoption, sperm donor, or simply the boy next door. (I'm not sure my metaphor is the appropriate one, but I'm in a hurry.)
And.... no. No, no, no! I am not discussing formal marriage primarily because I do not subscribe to the social insanity. I am formally married to my spouse because she wanted it for legal reasons. (Notice the word "she" is not capitalized.) "Till death do us part" is a joke, and not a very funny one, at that. Just wishful thinking; like praying for cake on a desserted island without food. (Misspelling, intentional.)
Bonding between two or more intelligent beings is a bonding involved heavily in the word "Love". Sexuality can be, but is not required as, icing on the cake.
Finally, yes, I'm hungry. But I'm going for a bologna sandwich instead of the sugar in cakes that my doctor tells me to avoid. Maybe.... pizza?