The reason for disinheritance is said that Masamoto HOSOKAWA judged it is hard for Sumiyuki to succeed as Kanrei by 15 years old, as Sumiyuki HOSOKAWA was a noble and was not quick-witted.
廃嫡の理由は、細川澄之は貴族で才気に乏しく、15歳までに管領を継がすのは難しいと細川政元が判断としたことが原因と言われている。