They're all dislikeable characters, but shiv was the most jarring. She was playing the otherside because she thought she'd get out on top and get one over Kendal, even started gloating about how she'd played it better and had won. Matsson was never going to hire he was quite clearly just using her, and even when he shafted her in favour of Tom, she in her own words couldn't stomach Kendal winning and voted the deal through. Not because it was the better option, but simply because she couldn't handle not getting her way.
She had no redeeming qualities whatsoever. Roman was an absolute spoilt rich kid cnut but atleast he had wit and was somewhat funny. Kendall was nowhere near as good as his father but atleast had some business acumen, and despite the last few scenes demonstrated care for his siblings. Absent father but still cared for his children.
Shiv constantly cheated on her husband, constantly schemed against her brother's to get her own way and was overall incredibly unlikeable.
If you want to get into the issue at hand of hating women in these types of shows, the issue isn't that people hate them. That's normally justified by their actions. The issue is the way that they're written. Write women characters better and don't feed into tropes. Seen it time and time again, looking at you Skylar. Bitch.