I am not in the least surprised reading Dozois' comments regarding Vance's supposed racism, sexism, and colonialism. The (so-called) social justice warriors are constantly standing vigil, looking for that which they deem "offensive" or "problematic" or which contains hidden "micro aggressions" or shows a lack of "diversity". SF/Fantasy in particular has been singled out for their ire, since it is, in large part, written by heterosexual white males. It seems their scrutiny as well as their sensibilities are retroactive since they will not hesitate to judge a writer of, say, the early 20th century by their modern standards. 

I am not one of the sad puppy or rabid puppy followers, nor do I consider myself on the opposite side. I like to think I am on the side of common sense. But I, too, will be judged by these arbiters of all that is good and decent, and found wanting, no doubt. Oh, well. No one's perfect.

Felicibus brevis, miseris hora longa.