How is it great for battery life? When applications are inactive, they're already not using CPU cycles. Task-switching involves focusing context, which does eat

How is it great for battery life? When applications are inactive, they're already not using CPU cycles. Task-switching involves focusing context, which does eat up CPU time, whereas with standard UNIX multitasking, switching between tasks doesn't switch context. You could remove the context switch from the equation, but then you'd end up with a setup similar to the current multitasking system, so it's all for nought.