Here's something interesting. Although his debt was high,
his assets are higher. (There are similar sources, but Luxist had the most condensed version.)
According to the link, Neverland ranch could be worth anywhere from $70 to $90 million. His co-ownership of the Beatles' songs, as well as his own, are supposedly worth anywhere from $500 million to $1 billion. And if he had been able to go on tour, that could net him another $50 million to $400 million.
Add it all up, and... even $500 million of debt doesn't seem so bad!
In fact, from a business stand-point, all the scandals that tarnished him as a brand probably hurt his bottom line more than anything.
Well anyway, may he rest in peace....