I made a slightly illogical, academic observation on another forum, but I think it gets bluntly to the reason why this is horrible. If animation lost Miyazaki at 46, he would have been in production of My Neighbour Totoro. No Kiki, Porco, Mononoke, Spirited Away, Howl, Ponyo... I can't help but voice the opinion that the best was yet to come from Satoshi Kon, and that we've just been deprived of something spectacular.
Or just be grateful for what we got, because he had a pretty damned good track record.