This made sense to me, as they're all basic drives and speak to the human condition. What gets more primal and raw than sex and violence? They're definitely attention grabbers. Even if these happenings make us uncomfortable, we often can't look away, at least for long. They grip us and hold us in thrall.
And food? Not only do we need it to live, but food can be highly sensual, say, in a romance or highly disturbing in a horror flick.
For romance readers and writers, the most important basic need is undoubtedly love. But other primal drives add conflict and richness to a love story that would otherwise be lacking.
Because ultimately, we humans always want something, and our fiction should portray that. I guess it really does come down to GMC (goal--what the character wants; motivation--why character wants it; and conflict--what's stopping the character from having it).
So everyone go pick up a good book and get your drive on!
Couple eating apple: Image: photostock / FreeDigitalPhotos.net