I think romance is an important part of the character and the lack of it is definitely something that's noticeable compared to the Spider-Man cartoons that did have it as an element, as the relationships and character dynamics on this show sometimes don't seem as deep or as meaningful as they could be because they have to keep things "platonic" all the time.
It definitely hasn't helped Mary Jane's screentime any, where she's given less and less focus up until the very end (Ultimate Spider-Man) or just outright ignored (this show).
It even hurt Felicia/Black Cat since, without her relationship with Spider-Man, she basically becomes a one-off villain.