"They should move out of Steve Ballmer's basement and make their own OS." and "Why do they want to make software for platforms when their competencies are on hardware?" at the same time.
They're leapfrogging to a niche market of going from hardware to security on the Windows platform. What's the gain in getting into an specific platform's flaws (antivirus) and development environment? That's the corner of the platform itself, not to mention the scope of the OS industry.
If they want to do software, they should develop a OS, maybe for Atom or some kind of mobile platform or otherwise.
"They should move out of Steve Ballmer's basement and make their own OS." and "Why do they want to make software for platforms when their competencies are on hardware?" at the same time.