Your examples are not comparable to abstaining from sex.
It would be like saying "don't eat any food" and "don't use locomotion to move from point A to point B."
> I just disagree that eating, sleeping, or sex are "core" desires.
I may not be understanding this. Eating and sleeping are obviously requirements for anyone's life, and sex is required for the continuation of all life.
But all of them appear to be "core" desires to us because they are immediate, potent forces. But just because these appetites are strong doesn't make them necessary. Everyone has to eat something but (in the general case) "you don't have to eat that *right now*" is true. Same with sleep - you don't need to sleep as much as you think you do (and you probably should be sleeping some times when you don't feel like it). So we come to sex. Is sex necessary for the continuation of the human race? Yes. Is it necessary for you to have sex at all? No. (Again, in the general case).
You are conflating species and individual survival. Sex is required for the continuation of the species, but not for the survival of an individual in that species.