I'd have to agree to a large extent. Female OCs tend to bear the brunt of these sorts of accusations, and as someone who writes both het and slash, I can honestly say that a lot of the people that read and/or write slash or yaoi are inclined to hate any female character on sight. There is also a great deal of wish fulfillment that comes into play with the female OCs. For some, they are who the author would love to be, and that causes the author to exaggerate the OC's abilities. For others, I've seen it degenerate into a sort of virtual self-loathing, with the OC representing everything the author would change about themselves. Either way, the accusation of "sue-hood" is one that is used too widely, in my opinion, to bash any character that a reader doesn't like, even if only because that character is the "wrong" gender.