It's more to do with the way women die in these games. Male characters usually have, well, a character, a personality and some role in the story. Their deaths have meaning and relate to them, and are at least somewhat realistic.
They do?!! Really, what FPS/TPS have you played lately where all the fodder have personalities and roles in the story beyond being guys shooting back at you? Let's be frank, the GRAND majority of all characters in a game are empty shells used as obstacles or background decoration, regardless of gender of the character. You bring up Princess peach, but how much personality does Bowser or Mario have, nearly none, hence why it is so easy to swap pretty much any of them with other characters without having any major impact on the game.
Now, there are definitely examples of terrible usage of female characters in video games, but don't grossly over generalize. That's one of the biggest issues in this situation, one side or the other taking this as an absolute across the board, and when you do that, yeah you'll tick people off as that's a pretty bad misrepresentation of the situation.