Steve Jobs の辞表

　８月２４日に　アップルのスティーブ・ジョブズ 氏が　アップルのC.E.O.を辞任しました

http://bits.blogs.nytimes.com/2011/08/24/text-of-jobss-resignation-letter/

I have always said if there ever came a day when I could no longer meet my duties and expectations as Apple’s C.E.O., I would be the first to let you know. Unfortunately, that day has come.

　と書いてありますから　健康上の理由でしょう