[user104658]

It doesn't make for a bad alternative take on the Joker but it does fundamentally alter the character. If he is just a psychologically broken man twisted by trauma then he is simply -not- chaotic, his actions are a very explainable form of mental illness.

The classic Joker isn't broken in that way, his actions don't come from a place of pain or anger, his violence has always come from a totally random place of "Well why not?". His sheer unpredictability is vital to the character as a villain for Batman because Batman is "the great detective"... A genius who can see patterns in everything and solve these questions... But he can never predict The Joker.

Like I said I haven't seen the film and it may well be a fantastic version of a character with similar traits, but I can't accept it as an origin story for THE actual Joker (and the film makers have stated emphatically that it is not that and not intended to be that).