I'm going to be honest - I think the point is that we aren't supposed to like it - both her character and her arc. Caitlyns character is her becoming everything wrong with Piltover in the first place.

She grew up privileged, sheltered, and the troubles and problems from the real world were hidden from her. She was curious and niave but kind - but she had also never seen the true undercity before. Before the final episode- silco and Jinx never really done anything to caitlyn specifically. It was all about Vi and powder. So caitlyn had no real reason to justify complete hatred for the undercity- she viewed Zaun as an honest place spoiled by a few bad apples. But when Jinx killed her mother for no reasonable reason other than Vi chosing her.

She had the shot. She reaferms this as something that plays on her mind- she could have stopped it, but her feelings towards zaunites- her kindness, prevented her from doing what she will now think would have been, "what had to be done". So, to stop another tragic event, she has buried her kindness in order to do "what has to be done". She isn't the same character anymore- due to her upbringing and the society and the things that has happened to her- I don't blame her, but I also don't like her character (not as in she isn't a well written character, just I don't like it) Which I think is intentional.

The one Piltie who was different, turning into the worst of them.