Why does everyone think Sinofsky left because Windows 8 was a failure?

I know not everyone think this but as Ive read comments on several articles from several sites people are commenting its because Windows 8 is a failure. Im not going to get into weather it is or not but he left because he was, for lack of a better word, hard headed. According to allthingsD Sinofsky was becoming more disagreeable with other execs at the company.

http://allthingsd.com/20121112/breaking-windows-head-steven-sinofsky-to-leave-microsoft/?mod=atdtweet

Also Cnet had an article a while ago talking about his polarizing leadership skills. http://news.cnet.com/8301-10805_3-57536905-75/steven-sinofsky-microsofts-controversial-mr-windows-8/

So it wasnt because Windows 8 was a failure its because he had disagreements with many execs in the company