Si Lingtian's thoughts were completely ignored by Si Yuchen, which was also the best choice Si Yuchen could make for himself.
If one must say why Si Yuchen opposed Si Lingtian, it would be because he had other thoughts in his mind.
Si Lingtian's idea was to have Si Yuchen replace him, become the Family Head of the Si Family. This way, all the burdens and responsibilities of the Si Family would also become Si Yuchen's responsibilities.
Si Yuchen's dream was to become a doctor, no one could bind him, and no one could force him to abandon his dream.
Si Yuchen didn't care what the Si Family, this large family, might eventually become. Even without him as Family Head, the Si Family wouldn't easily decline after a hundred-year legacy.
The reason why Si Lingtian was so earnest in wanting Si Yuchen to inherit was that he believed aside from Si Yuchen, no one else could be qualified for this position.