When people talk about true love they usually have the image of a long term, loving relationship in mind. However, this is not what is most prominent in the information we receive each day. Marital breakups, spousal abuse, infidelity, etc. are the focus of attention while the fact that far more people are going about their daily lives happily married is usually overlooked. This is true of both the media and plain old gossip.
The fact that a co-worker, neighbor, relative, friend, etc. is having problems or has done something wrong makes for good gossip, or the evening news if it is big enough and juicy enough.
While the fact that many more people we know are happily going about their daily lives rarely merits comment. In fact the only time such everyday things stand out is when they are the exception – when the rest of the neighbors are filing for divorce and the Joneses remain happily married that might warrant a comment or when all of the couples in a group except for one couple spend all their time bickering with each other, then the one couple that is not bickering will have some limited gossip value. However, things that are tragic or wrong or both make for far more interesting topics for journalists and gossips than good things.
Also, because it is more exciting, Eros has long been a theme for art and literature while Agape, being more common and more mundane, is usually only discussed in self-help books.
This is why almost every story, novel, stage play and movie dealing with romance ends with And they lived happily ever after. However, had the author continued on to describe living happily ever after they would have put the audience/reader to sleep because, while living happily ever after is great for those is great for oneself, it is boring to read about or view it in others. Sure, we may be happy for them and even be slightly envious of what they have, but for entertaining diversion most of us want something with more action, suspense and tragedy.