This assumes that the only thing worth caring about with Yahoo is the company itself, and Marissa Mayer, the company's final CEO.
It ignores the millions of users and paying customers who relied on Yahoo for their email, their groups, their lists, their photos.
In my case it's photos. I have 65,000+ of them on Flickr, which would still have market value as a stand-alone company or service if Yahoo hadn't insisted on getting rid of Flickr's namespace for every member, and substituting a Yahoo one that will cost (by the estimate of Stewart Butterfield, one of Flickr's founders) the better part of a $billion to un-fuck. (A bad decision that predated Marissa by many years, by the way.)
Here is the important fact about businesses that most business journalism fails to grok: no company matters more than what it does for its users and customers. And there is almost nothing in coverage of Yahoo's travails visiting that simple fact. Or why that's what's really worth crying about in Yahoo's failure.