Are there really "so many" people who say both? I haven't seen that particular argument, but I tend to zone out when it comes to hardcore game-play talk.
I think, if anything, the main difference between the two situations has less to do with Natalie and Laurel, and more to do with Russell and Wendell/Dom. A big argument against Russell isn't just that he wasn't nice, but that he was also a terrible player who didn't understand or acknowledge the basic concept of the endgame, whereas Wendell and Dom were generally seen as good players (Dom just perhaps got a little too "dom"inating, har har, at the end). Both Russell and Wendell/Dom ate the edits of their seasons, but perhaps people feel that was more justified in the latter case and are therefore less compelled to defend Laurel, whereas they feel that Natalie's game was shafted, edit-wise.
Despite my use of "whereas" and "therefore", I am not a lawyer. Just pretentious, apparently.