If Jerry Yang did not have the credentials of Yahoo founder/CEO at the time, do you think Jack Ma would've let him in? Alibaba was growing very fast at that point, and one big reason they let Yahoo in is its brand.
What's up with that condescending "Engineers :)" remark, which has nothing to do with whether Jerry Yang returning to Yahoo made a difference in how Yahoo recovered from its demise.
That actually happened before Yang returned as CEO:
"In 2005, under Yang’s direction but before he took over as CEO in 2007, Yahoo! purchased a 40% stake in Alibaba for $1 billion plus the assets of Yahoo! China, valued at $700 million."
