Well, sure, I never said that falling off of buildings was a Joker-only thing, just that he seems to do it a lot. It's a scene that I keep see being repeated with that particular character, so I was just wondering why that might be (because I don't see it happen with any other Batman villains).
Well, it's not an homage to a specific scene, as far as I know. Maybe it's just that it's a particularly "villain-worthy," dramatic fate, and the Joker is Batman's chief villain, not to mention one who seemingly dies a lot, more than most in Batman's rogues' gallery.
Although the mortality rate in the movies is a whole lot higher. Didn't Two-Face fall to his death in Batman Forever
? Heck, come to think of it, Burton's Selina Kyle fell to her death before
she became Catwoman.
I think a case can be made that the most prolific killer in cinematic history is the Earth's gravitational field.