That's because to them Sakura is a kitten who doesn't put out and beats up their insert character (or denies their insert character the man she is entitled to have.) So she is an oppressor and therefor can't have suffered being the one who causes suffering, cannot have anything that makes she sympatric, and ultimately is just evil and you should feel no guilt when something bad happens to her because it is justice to them.
Oh I know. That is the actual reasoning for any tsundere, but again the double standard here is that others are actually encouraged for their love interests, even in the series it self. If you're talking about tsunderes with a ball-busting attitude, you can't look further than Temari yet she has many fans that want her with Shikamaru ¯\_(ツ)_/¯ And don't get me started on other series (cough cough* Black Clover *cough cough*)