It's indeed true that some great reviewers have gone, but it is equally untrue that ' all' of the great reviewers have left. But let's not overemphasize this or keep it in an improper perspective or get pompous about it- it's not like there will be one great reviewer left dancing in a cemetery with gravestones of well regarded reviewers saying "I outlived them all" like Belushi in that famous SNL skit!
In the words of the Flaming Lips:
"And...everyone...you know..someday...will die... ( Ten helpfuls and a crate of pomegranate juice to whoever can correctly identify that quote)