This is actually not an issue with the script.
Initially, the script had Zhou Yun and Xu Siyao engaging in several confrontational scenes, subtly competing and clashing with each other.
However, He Yong soon realized Xu Siyao's shortcomings in appearance, and thus he proposed to reduce the scenes where the two appear together on screen. Eventually, the script was majorly revised; Xu Siyao basically had no storyline transitions involving Zhou Yun, only some unavoidable shared screen time and dialogue.
Consequently, the character only retained her natural relational antagonism but lacked substantial opposition in the storyline, indirectly placing Xu Siyao's character in a neutral position with the audience.
Even just by portraying a daring, love-struck young lady, following the trends of film and television shows over the years, she would definitely be favored by a group of viewers; many supporting characters have overshadowed the main characters this way.
