I'm constantly bugged by people's use of the word "multitasking" to refer to things it really bears no relationship with.

I'd say pretty much all modern devices that are usable at all support multitasking.

Proof; ssh to your device or open a console and type "ps aux"
What do you see?

If the device UI & launcher supports only some braindead notion of interaction model, well do you have to live with it, huh?