The best explanation I can come up with is that any male graduate of an MFA writing program has been thoroughly brainwashed by militant campus PC and is incapable of having good sex let alone writing convincingly about it. Then consider the sort of (usually female) characters who dominate the ground floor of the publishing world. Hell! They may be afraid to submit anything involves sex, which is, after all, just ritualized rape, etc.
Just bethink of those whiny-voiced castrati who call up the conservative talk shows... Ewwww!