Ah, that one. Actually I saw that video and I recall she meant that yeah she liked BvS but she was making a speech about not what she'd want/like but about what would be good for WB/DC business wise, and business wise she feels many people won't give future films a chance if Snyder keeps directing them so in that sense he needs to go.
She probably bowed down to the majority opinion. Popularity is the lifeline of a youtuber. I remember that guy Tyrone Magnus saying a lot of people unsubscribed because he said he liked BvS more than Civil War.