I will say though the suggesting that people only went crazy over Ledger’s performance because he died is BS of a magnitude I cannot abide.
It was a good performance.
People also overrated it. The reasons for that may be varied but I believe it mostly happened because he died, and if he hadn’t we wouldn’t have heard nearly as much about how great it was.
I think people rated it just fine, you just didn’t like it as much.
There was certainly some degree of attention to it because of his death, but if it wasn’t great, people wouldn’t have cared. Actors release movies posthumously all the time and people almost routinely never care.
At the time it might have been hard to tell because emotions were still high, but it’s now been almost 9 years since and the performance is still widely considered the best ever given in a comic book film. I think it’s pretty clear at this point the quality of it has little to do with the outside circumstances.