Because love is one of the strongest human emotions when truly expressed with meaning. So as long as music has been around, and as many musicians as there are, that's a lot of songs. Everyone experiences it a little differently so people try to write about it differently. The majority of the world and music market likes to only hear songs that make them feel good and love songs do just that, also back when the record industries were first getting mainstream certain topics considered possibly taboo, offensice, or to vulgar were forbidden from being sung about so many old classic songs tend to be about love becase in some senses it was the only thing allowed to be written about. It's an easy thing to write about that everyone can relate to in some way...:thumbsup: