There is a solid no nonsense reason for what we call "love"
Attractiveness is critical. Anatomical ability to seed and birth progeny to provide for species survival are critical. "Love" can then proceed.
Mating and attraction rituals
Each culture has a specific set of attraction rituals prior to the act of mating that assure proper seed deposition. Attraction criteria come in before actual mating.
Male seeding and female pelvic dimensions.
Prior to gestation, the male and female gamete must be compatible to form a zygote. There a limiting anatomical considerations which must be met to assure compatability.
Cultural and physical requirements need to be compatibe.
Once the criteria are satisfied, the hormonal and neuropsychological phenomenon we call "love" commences. Those visceral and coporeal responses are "love"
Species specific fertilization
The two gametes must form a zygote for the force driving us to continue as a species This is the way homo sapiens enact immortality.
Yes, "love" does exist. "Love" is