10 Problems With The Joker Nobody Wants To Admit
4. He Isn't In Love With Batman
So why exactly is The Joker so obsessed with Batman? If you throw out the mystical mumbo jumbo of how one cannot exist without the other, that they give each other purpose and all that malarkey, and instead focus on the actual explanations...well, usually writers just plump for the rote The Joker is in love with Batman.
It's a concept that has long been in the background, but was brought to the fore with the recent Death Of The Family storyline where the Caped Crusader freaked out his nemesis by calling him darling; itself a call back to The Dark Knight Returns, where he came out of a coma after seeing his love return and uttering the same name. Now that motivation is either wrong-headed, offensive, or somewhere in between the two.
On the latter point, it's sort of perpetuating the idea of homosexuality as a dangerous fringe form of sexuality that lunatics and perverts indulge in. The former is just bad writing. The Joker is in love with Batman? Then the writers who depict him as such have a very shaky grasp on what love is, and you almost certainly shouldn't date them.
Harley Quinn's dangerous romantic obsession with The Joker makes a certain kind of twisted sense. The Joker being in love with Batman on the basis of how he treats Batman - doesn't follow any kind of logic. Even a crazy person's.