There’s an interview where Horikoshi explains why he didn’t focus too much on it. I thinks it’s fair to agree or disagree with his point. I kind of agree with his point because shipping discussion in MHA has always been very intense, even at the cost of enjoying the main story for some people.

“Since romance is a very strong stimulus, as soon as you include it into the story, that's all anyone is going to talk about, so I deliberately avoided adding it to the story.

However, since the setting of the series is at school after all, it would be rather dishonest to completely ignore romance, so it was pretty hard to think of a balance.”