Exactomundo! Jolla would indeed be ill advised, not to use multitasking. Sooner or later all mobile OS will have to overcome such artifical restrictions, because the hardware is getting more and more powerful. These devices will replace more and more PCs or notebooks, if the user can use them like such simply by attaching HMI devices (like a docking station).

One comment to the argument "wild running apps drain the battery": Wouldn't it be enough to display a coloured circle somewhere near the battery symbol to indicate the system load? Even some cars indicate their current fuel consumption, so the driver can shift gears to save fuel. I think almost every similar approach would be more reasonable than artifical restrictions like "optimised multitasking", however intelligent and sophisticated designed and implemented that would be.

One of the most convincing arguments for multitasking has been presented by Microsoft: They were not able to use Skype (which has been bought for a huge amount of money) on their Lumia devices for the simple reason: They needed an interface to compensate missing multitasking. This is ridiculous.