I really do not have anything against love triangles, I actually kind of enjoy them as long as they are not overly annoying. Probably because of VVV
I was in a love triangle once or twice in high school. They usually happened unknowingly and the first time ended up with the girl giving me a rejection/hate letter one day out of the blue. She was super friendly to me for months and I considered as a friend. Turned out she had a crush on me while I had a crush on a girl a grade above us. Surprised the hell outta me!! We became good friends later though.
The other time I made the other girl cry unknowingly. I forgot what I said but the girl in the above story punched me (not anime style, in the arm, and it hurt iirc) for it. I had no idea who she was at the time and I suppose I said something about not ever being interested in her or something. Later on we both had this... strange vibe of attraction toward each other but nothing ever came of it, and I'm glad.
So I guess that's why I don't really have any issues with them. (That is not mentioning the numerous times in the past 6 1/2 years where other guys tried to steal my girlfriend away knowing she was with me, and even met and shook my hand!! The nerve!!! And yes, if in the past if I found out the girl I became attracted to had a boyfriend I would totally back off, it's not my place to interfere and because I would not like someone else doing it to me.)
Besides aaaalll of that. My main problem with the romance genre is the stories where the main character is always thinking about getting a girlfriend or sex and that's all that they ever think about. There is no character development outside of that. But what is even much much worse is when the main love interest (usually a guy) sexually assaults the main girl or nearly rapes her and all of a sudden she's like, "OMFGOZH*(#($*H(F*#(OIEH I LOVE HIM!!!" On top of that the main guy is almost always a complete asshole/douche bag and whenever they bully or tease or harass the main girl she runs or pushes them away. Then they spit out, "you're a coward. I did nothing wrong. This is all your fault we are like this." Constantly humiliating and treating the main girl like an object or whatever. The sad part is is that the main girl is usually a pretty good character but ends up becoming some weird love slave who all of a sudden cannot do anything without the douche bag love interest. I've had so much trouble finding decent het romances because of this problem.
It's also a bit of a rant because I just dropped Hana Yori Dango mid way through Vol.26 and went through a few other similar "romances" just before it.