(On iOS multitasking)

That statement is wrong. PalmOS closed applications completely, then reopened them. Much as iOS 1.0 did (although even there the kernel supported multitasking and some of Apple's own apps did it). There was zero multitasking in at least the PalmOS versions people would be most familiar with.

There are upsides and downsides to both approaches (full multitasking, vs controlled iOS style). The upsides to iOS are really the much better control of battery and memory usage. A real compromise for a full pocket computer could be to have iOS limitations when on battery power, and full multitasking when on the grid. I don't really fancy calculating fractals in the background when on the move, sucking my battery...