Here's part of what Joshi wrote at his blog:
It has come to my attention that the World Fantasy Convention has decided to replace the bust of H. P. Lovecraft that constitutes the World Fantasy Award with some other figure. Evidently this move was meant to placate the shrill whining of a handful of social justice warriors who believe that a “vicious racist” like Lovecraft has no business being honoured by such an award. (Let it pass that analogous accusations could be made about Bram Stoker and John W. Campbell, Jr., who also have awards named after them. These figures do not seem to elicit the outrage of the SJWs.) Accordingly, I have returned my two World Fantasy Awards to the co-chairman of the WFC board, David G. Hartwell.You can read the rest, including Joshi's letter to Hartwell, at the link above.