It's not a proper love story, no, and Shakespeare didn't intend it to be.
The tragedy is that these two families are so obsessed with fighting they're ignoring everything. prince's decree, everything. The tragedy is that it took their childrens dying for Lords Capulet and Montague to figure their shit out and stop killing each other.
It's in the opening, really, how it lays it out, two households, both alike in dignity...
THEY'RE the protagonists, not so much Romeo and Juliet, the foils for the tragic scene.