Carol Bartz of Yahoo was fired on Tuesday, which means there are now officially no female C.E.O.s of major technology companies. The number of male A-listers in Silicon Valley who attended Montessori schools (Larry Page and Sergey Brin of Google, Jimmy Wales of Wikipedia, and Jeff Bezos of Amazon) is four times higher than the total number of female A-listers (Sheryl Sandberg, the chief operating officer of Facebook).

As Ken Auletta explained in his wonderful profile of Sandberg, there are many explanations. Coding is perceived as a boy thing; women often step away from their jobs to have children; the place is sexist. Bartz, however, failed on her own merits. She took over two and a half years ago and the company has not come up with one brilliant idea since. The stock, which has been flat since Bartz arrived, surged when she departed. On Wednesday, shares climbed more than five per cent. Nothing in her career became her like the leaving of it.

If Bartz had run a paper-clip factory, she’d have won awards. She improved operating margins. She fired lots of people. She cut fat. But things change fast in technology, and companies that don’t innovate wither. Their products become obsolete and their coders leave. Yahoo missed out on every tech trend of the past few years: social networking, location service, group deals, passive gaming, status updates. Yahoo once was the place that organized the Internet. Now, it’s a place for fantasy-sports leagues, stock prices, and inscrutable purple signs proclaiming, “It’s You.” What is Yahoo? Neither Bartz nor other executives have proven able to coherently answer that question.

Yahoo hasn’t played well with others, either. Yahoo’s most valuable asset is its stake in the Chinese tech company Alibaba. But Bartz got along poorly with Alibaba’s leadership and, this spring, Alibaba spun out one of its most important businesses behind Bartz’s back. In the summer of 2009, Bartz used a giant purple pen to sign a search-engine partnership in which Microsoft would provide the technology to power Yahoo’s search engine. The integration has not gone well, and Yahoo’s market share has dropped since.

Bartz cusses people out, and, at her previous job, as C.E.O. of Autodesk, she was known for beginning meetings with, “Tell me why I shouldn’t fire the whole lot of you.” For quite some time now, she hasn’t had a good answer to her old question. And on Tuesday, Yahoo’s board finally acted.

Bartz, with Steve Ballmer, signs the Microsoft deal in 2009. Photograph: Yahoo, Flickr CC.