>>4800047While his death torpedoed the film to lofty heights it likely would have never attained otherwise (especially the interest over the idea that the stress of the Joker role somehow contributed to Heath's death), it still is a solidly written crime movie, well-paced, with a well-composed sountrack, and well-composed cinematography. Riding on the coat tails of Batman Begins' relative success/praise and taking advantage of the, then, underutilized "realistic superhero" film genre that audiences didn't know they were subconciously craving, it wouldn't have needed much else to help it along. Nolan also released the film at a very lucky time, mid-recession America, where the tone of "solidarity" and being triumphant over chaos despite human nature was a timely one.
Had Heath still lived, Id like to think the film would have still been met with relative sucess in comparion to other batman films past and present and still would have been influential enough to lean the superohero genre to a more realistic edge that it still currently standardizes.
That being said, doing too much if one thing is one of Hollywood's greatest sins and after the weak DC Cinematic Universe treatment Id say a good portion of comic book fans and non-comic book fans want a return to more campy, colorful films these days.
Funnily enough, even back then the Tim Burton's batman films were seen as being "too moody".