Aug 24, 2013 · 4 minutes

So Steve Ballmer has done what many have clamored for and fewer saw happening so soon: He's resigning. Viewed one way, he's being pushed out. From another (Ballmer's view), this is simply the “right time” for a transition. Either way, the Steve Ballmer era is over. And it wasn't Microsoft's most glorious era. Ballmer is the face of Microsoft in middle age. A man whose image pales next to the magnanimous philanthropy of the middle-aged Bill Gates. And even more against the sociopathic ruthlessness of the younger, leaner Bill Gates.

As news of Ballmer's resignation spreads, you will see pictures, GIFs, and videos of him sweating it up, saying reckless things, hopping like a hairless gorilla. This was the unseemly side of the unwavering passion that Gates saw in Ballmer early on and that was a turbine powering Microsoft forward for decades. It's easy to want Microsoft to run without this particular turbine. It's harder to imagine what that will actually look like.

Ballmer never seemed to be much of a visionary, not in the way Gates or Ray Ozzie was. It's hard to imagine Ballmer writing a book called “The Road Ahead,” unless it was a manual on managing road rage. But for all the problems Microsoft is facing, it's also remarkable that the company is performing as well as it is in enterprise software, entertainment devices, and servers. These areas are helping Microsoft manage the post-PC world better than aging tech giants, and the centrifugal force holding these pieces together was Ballmer.

News of Ballmer's departure jacked up Microsoft's stock 7 percent Friday, even though he may remain at the company for another year. But under Ballmer, Microsoft had performed well among its peers, rising 17 percent in the previous five years. That's disappointing relative to the 29-percent gain in the Dow, but other PC-dependent companies have fared far worse: Dell is down 45 percent, Hewlett-Packard is down 53 percent. That's largely because Ballmer has steered the company into growth areas like enterprise software.

For all Ballmer may have done right, however, he made three big mistakes. He allowed a fractured, dysfunctional corporate culture to fester inside the company, making Microsoft more of a fiefdom of warring states than a well-oiled corporation. He could never earn a dollar from the consumer Web, a huge area of growth and perhaps the most public side of the company. And he was terrible at cultivating a charismatic image as CEO.

He was Ballmer. The funny, sweaty guy on stage, not the executive who nurtured Xbox, Office 365, and Azure into successful businesses. He was the great hurler of chairs, the clueless heckler of iPhones, not so much the guy who tripled Microsoft's revenue and doubled its profit during his tenure.

My friend and colleague Adam Penenberg declared Ballmer the worst CEO ever, and I doubt he's alone in that view. I see it differently. The Microsoft that Gates built and left for Ballmer to run was one that was genetically incompatible with a decentralized world built on the Internet. So yes, Microsoft under Ballmer went from an industry colossus to an also-ran, but that was a trajectory set into motion when Gates was still in charge. Ballmer's biggest accomplishment may be hard to see, because it lies in what didn't happen: Microsoft didn't fall apart, like HP and Dell have, after Gates left.

In recent years, Ballmer took unprecedentedly bold moves inside Microsoft to create a mobile OS that could compete with iOS and Android. With Surface, he made an iconoclastic push into hardware without alienating Microsoft's other OEMs. With Windows 8, he built a bridge between the Windows that was a dynasty in an bygone era to a Windows that could compete in a future one. It's still too early to declare all those efforts a failure, although some early signs aren't encouraging.

The sheer ambition behind that change, and that fact that Windows 8 launched with relatively few glitches, is worth noting. One time giants like BlackBerry, Palm, and Nokia have fought for a place at the mobile-OS table with far worse results. The fact that Microsoft is even still in the mobile game is a notable achievement, even if it wasn't what investors were hoping for.

When Ballmer leaves, the centrifugal force that held the disparate divisions together may well go with him. Microsoft's board may claim it will continue in the direction Ballmer started, but it could also be that Ballmer's departure is the first in a series of developments that will end up with the company broken up.

Breaking up Microsoft is an idea that has floated around for years, even in the monopoly days, but it's been gathering steam on Wall Street in recent months. Microsoft's cheap valuation (3 times future sales, 11 times future earnings) is low enough to draw the attention of activist investors. In April, a Goldman analyst suggested a breakup as a possible scenario. A couple of months later, a Nomura analyst made a good case for it to happen.

The jump in Microsoft's shares Friday might say less about the post-Ballmer era and more about the value of Microsoft in pieces. And so Microsoft's next CEO may not be someone skilled at uniting its myriad businesses, but rather in selling them off. Or it could be a number of CEOs. Frustrated Microsoft investors are getting what they've wanted for years: A Microsoft without Ballmer. That post-Ballmer Microsoft, however, may look very different from what many have imagined.

[Illustration by Cam Floyd for Pandodaily]