I really despise arrogant people. And she is the embodiment of empty arrogance and confidence born from deep insecurity.
Yeah, that's the intention. You hate Zara because the game wants. Her arrogance and confidence is just a mask for her insecurity, that's what makes the character interesting. Her mother being a bitch and remembering her that she will never be enough, a big sister more inteligent, talented and gorgeous than her (Zara is more my type but that's the idea) and a father that wants a boy and not a girl makes her extremely insecure. That's why she needs to win, that's why she needs to fake confidence and that's why the MC, who treats her like an human being and show her what real confidence is breaks her mascara. The scene when
you pass the basketball to her is one of the best scenes in the game because the MC doesn't even think about manipulate her like usual, but he tell exactly what Zara has needed to listen all her life: you are enough, I believe in you and you couldn't fail me ever if you tried (paraphrasing).
You can hate Zara if you only saw the first part of her character and presentation, but why she is so loved is obvious, the game show you how amazing she is and how she just needs love and kindness, and why she deserves that love and kindness. Oceans is amazing making complex characters, and Zara is just one of the best right now.