i never said it was just to have babies, the whole reason the desire for it exists is to continue the species, the species would die if it wasn't pleasurable, nobody and nothing would have sex if it felt like getting your teeth cleaned
there are plenty of indicators of a person having strong genes, saying a person is good looking is the same as saying they look healthy and have good genes
what is generally considered attractive? clear skin, lean body, symmetrical face, youth, at least average height short people get bullied and are more likely to be victims of a crime
what's generally considered unattractive? overweight body, face that lacks symmetry, bad skin, old age
all of these are indicators of poor health and bad genes
E
You reduced sexual intercourse to procreation. That's what you said.
Why do people watch porn? why do people hire strippers? Why do people masturbate? Because sex is also recreational; people like and need to please themselves.
And I include watching bodybuilding here right next to stripping because it is also a sexually-charged form of entertaintment where men enhance their secondary sex traits for public exhibition.
Again, most of heterosexual sex is recreational with no intention to make babies at all. It is simply to release sexual desire, release tension and feel happy afterwards.
You cannot know who has "strong genes" unless have a medical analysis in your hands. Attraction is subjective. Your view of attraction and genes sounds very emotionless to call it something, like solving a math problem when humans are not like maths.
Sexual intercourse is not a heterosexual property. You are not obliged to have sex with someone you don't want you; just don't try to tell others who to love or have sex with.