For home users I'd say the biggest thing that keeps them on Windows is gaming, but Valve have made excellent progress at getting games to run on Linux now.
For business users I'd say the biggest thing is Active Directory - being able to manage and micro-manage a fleet of hundreds or thousands of PCs by a small team is highly desirable.
For business users I'd say the biggest thing is Active Directory - being able to manage and micro-manage a fleet of hundreds or thousands of PCs by a small team is highly desirable.