I'm not extremely happy about the way some of the DC Comics writers have treated the Joker. Yeah, I know that in universe he's a mass murdering lunatic clown, but that's only one version of him; the Joker has gone through many changes over the years and been portrayed in a few different forms. Officially, he has no origin story and is pretty much your quintessential scary clown villain, ideally with a dark comedic twist.
It's not really that way for the superheroes, though. Batman, for example, has a well defined origin story, and the character stays more or less the same, in essence, even though he's updated from time to time. You still never lose what makes the character "Batman." It's the same with the other well-known superheroes, so...why not make a superhero version of the Joker that has a defined backstory and set characterization?
The Jokester from Earth 3 that appeared in Countdown to Final Crisis was a good example of this. Why not reboot this character and give him all of the good traits of the Joker (the sense of humor, the dark comedy, the Silver Age silliness, the crazily clever wit, etc.)?
The Joker's a great character in theory, but the changes the writers often make to him cause him to lose character development that could make the character even more interesting. Since making Joker something familiar might pose a problem in main continuity and mess up something DC wants to do with the character further down the line, why don't they reboot the Jokester character and give him all of the great backstories, quirks, and personality traits of the Joker we all know and love?