The Horrorific Trope of Unrequited Love

I confess--I always assumed that other people disliked the unrequited love trope as much as me, until I was watching Les Miserables with a friend (the anniversary special). I made a caustic remark about Eponine and my friend disagreed.

I still don't get it. Setting aside the stalker theme (when does Eponine becomes Kathy Bates?), it seems like such a blasted waste of time. 

Why not get on with life? Even if no one else will ever mean the same, why not, just for instance, go rock climbing, get a career, take over government, adopt a cat, plant trees, learn a language, visit archaeological sites, plan a trip to Mars, write a screenplay, get a degree or another degree, become a priest or nun, join a church and then become a priest or nun, learn to bake, learn to paint, paint houses, drive across country, find someone else to love, become a firefighter, repair cars, join the circus, join a club, start a club, watch all the black & white classics in the world, start a theme park, visit a theme park, hike, go to the beach, join a gym, patent an invention, become a private eye, learn to square dance, learn to kayak, visit another country, visit another state, volunteer for the Red Cross, train service animals, go to a ball game, memorize bones of the body...

The confession in Japanese literature has the merit of putting an end to the unrequited part--at least, the part that annoys people. Okay, you've suffered. Time to do something else. Granted, it often occurs far too late in the story not to cause annoyance in the first place. At least it is there. 

The problem isn't that the character suffering unrequited love appears weak and pitiful--the problem is the character suffering unrequited love appears to lack resources. And characters without resources are a tad...dull.