With Joker any sort of writing can be justified since he's 'LOL Crazy and Randumb for EVIL'.
The bigger issue is his fanbase which thinks that he's a symbol of 'the common man who was pushed into evil by a cruel and unfeeling society that refuses to admit its flaws and failures'.
DC seemingly catering to that portion of the fanbase with Punchline, a literal mouthpiece for their views, is also troubling.