Studios try to make their products appeal across four quadrants (male and female, under and over age 25). They have rules of thumb like "young men like action" and "young women don't like sex on screen, but it's OK if older girls talk about it". They try to put a romance in everything to hook that part of the audience that goes for it.
I remember discovering anime in the '90s, and was hooked for a while because it didn't try to please everyone. Some anime are for guys, some for girls, and you can pretty much tell which is which just by looking. Boys' and mens' shows tend to feature shallow female characters who are often aggressively sexual, and girls' shows feature unhealthily skinny male characters who are infinitely interested in the nuances of everyone's feelings, and if you're watching the wrong one you won't have fun.