That seems more like common sense than any protest. If you have an original version, and you change that version to something different, you are going to have to differentiate the two. FemThor or LadyThor seem like a pretty easy way to distinguish which one is being discussed.
Was it this big a deal when they had a black Captain America?
Black Captain America made sense, so no one complained.
I was apprehensive, but since he's keeping the Falcon stuff I'm fine with it.
Edit: Looking at Comichron's data, I have to wonder what the difference between "est. preorder" and "est. sales" is.
In addition, the 11 spot in 2008 was selling about 20k more copies than the current run and Thor(#6) was at #4 with 98254 units shipped to comic shops. Comic sales have generally gone down since sometime in 2008, with the frequent relaunches from Big2(particularly Marvel) causing spikes that increase sales of series. It's also interesting to note the prevalence of higher numbers in the higher spots in years prior to 2009. Anyone have digital sale data?