"If you care about how your room feels, let me tell you: it feels a lot better with an iMac instead of some ugly 3rd party monitor..."
Agreed. You'll see a lot of iMacs at design-conscious shops like art galleries and boutiques, and in architects' homes. These applications/people have different objective functions than many HN readers.
There is no real competition in this space (unfortunately), so people pay a premium. If you care about how your room feels, let me tell you: it feels a lot better with an iMac instead of some ugly 3rd party monitor. I didn't care about that as much, but now for me it is absolutely worth it.
Also, its a computer for people that don't like to invest huge amounts of time finding the "right" pc - I've started to appreciate that as well.