Aside from that, the sadness is the same as Dio/Lemmy - someone who you sort of figure will just keep going on forever, putting out an album a year. And because he looked 97 at age 59.
Not to be a douche but I'd never have wanted to meet the guy. Prindle loved him and admitted he was a total dick who hated everything. He also pounded his wife pretty badly IIRC.