Because arguments don’t happen in a vacuum where you can expect, nor should you expect, people to separate them out piecemeal and address them on your behalf (that’s further un-critical thinking, by the way). Rather, arguments inform other arguments and opinions inform other opinions.
Sylvanas being inexplicably and tiresomely overpowered is a common argument. Retconning to make her that way is another common argument. If that had been the whole of your argument, we could draw the conclusion that you were primarily against those.
But your argument led with handwringing over FEMALES and the TRENDS and all these other talking points. Hence, it gives us pause and makes us wonder: “Well, wait, if his issue is with retcons, why’s he talking about women characters so much?” And, thus, casts doubt on the conclusions you’re attempting to draw.
And you did all of that. No one asked you to. No one’s reaching. These were all your choices.
You made the decision to link those arguments. You made the decision to introduce them. And so you introduced doubt onto your own argument by choosing to conflate Sylvanas’ stupid cinematic with FEMALES.
To demand we not only not point this out, but not consider it along with the rest of your argument, would be the pinnacle of thinking uncritically.