Cliche: "The Boyfriend"

This has been what has been enough to piss me off when I was little and the "romance subplot" thrown in anywhere was stupid. Now when I am more mature and accepting, this idea still pisses me off. I mean, there's a character with no character that is only there in the story for a protagonist to fall in love with and stay together with no reason at all. It's everywhere I look now. Ice Age (4), Equestria Girls… At least when Romeo and Juliet did the bull "love at first sight thing", the relationship was later developed and was interesting for that reason. Now, I was never the "romance" kind of guy, but even I know that you have to have some reason for a relationship to work in a story besides from "just because", so I could just be wrong and a character involved in a romantic subplot and should be boring and should be attractive for no reason at all.