Microsoft's hardware—Surface, HoloLens, and Xbox—is "absolutely essential" to its future, according to former CEO Steve Ballmer in a new interview with Business Insider. That's because of the interrelationship between devices and the cloud: so many devices are supported by and dependent on cloud software, Ballmer feels that the company needs to participate both on the cloud side and on the device side.

Consistent with this idea, Ballmer continues to believe that mobile is an essential part of this hardware lineup. He says he "put the company on a path" toward having its own mobile devices and platform but that current Microsoft CEO Satya Nadella has "certainly changed that" by firing most Nokia staff and greatly scaling back Microsoft's phone-building ambitions. In the ex-Microsoft man's view—one shared by industry watchers, including this author—the new CEO "needs to have a clear path forward." Ballmer is "sure he'll get there," but he's not there yet.

The lack of mobile vision becomes particularly acute with Nadella's "mobile first, cloud first" slogan, which Ballmer describes as an "important perception point" that Nadella has done a "brilliant job on." He says that he meets with Nadella "four or five times a year," both to "brainstorm" and in his role as a shareholder. His position as a large shareholder affords a certain level of access to the company, but he says he's now an outsider. No longer working at Microsoft, he isn't privy to any confidential data.

This remains a cause of some discontent. While he speaks positively of Azure ("fantastic") and Office 365 ("the company's doing a great job") he has voiced frustration at the way Microsoft reports its financial performance in the cloud, previously calling the numbers offered "bullshit." His frustration on that issue seems unchanged.

Much of the interview looks at Ballmer's various non-Microsoft interests. He's putting together a currently unnamed site that offers what he describes as a "10K for government," breaking down its spending, revenue, and other financial metrics. Since leaving Microsoft, Ballmer has also bought a substantial stake in Twitter. The social media site has been suffering a lack of direction and a dismal share price performance, but Ballmer believes it's ripe with opportunity and offers "a lot of upside" and that long-term, it will "continue to be a great company." The largest part of the interview is a discussion of basketball. Ballmer's first big post-Microsoft act was buying the Clippers, and clearly he has a lot of passion there.