Perhaps your intense reaction stems from a misunderstanding of the meaning of "support" in this context? Host-mode is available and it should work fine but Nokia does not test it or provide for it as an officially supported feature. That means that it's not guaranteed to stick around and it's not guaranteed to be completely functional. That does not mean that it wont work at all.

The vast majority of Nokia's customers don't care in the least about host-mode support. They're going to plug their devices into their Windows machines and transfer files, perhaps sync with Ovi Suite and that's about it. Since that's the case and given that Nokia has limited resources to dedicate, then the extreme expense of supporting a feature like this (and host-mode is probably the most expensive feature they could choose to support) just doesn't make any sort of sense.

I don't know how you will provide power to the device while in host-mode (perhaps tapping into the USB pins in the battery compartment), but I am sure there will be no issues using it for as long as the battery holds out.