You seem quite stuck inside a box, unable to think of use cases for others.

Here's a use case from a business travelers PoV.

I carry a laptop around with me, with all the spare batteries, accessories and cables, it is a pretty heavy package.

if the N9 had an HDMI out, I could in most cases replace the laptop fully with the N9, and instead carry with me N9, mHDMI <> HDMI cable, foldable bluetooth keyboard & mouse.

This would save me up to 5KG of carry on luggage!

All the work data that I need with me can either be on device, or a VPN connection away on corporate LAN.
RDP works just fine for remote connecting to my desktop PC
Presentation? Just plug it into the projector.

For entertainment, I can then playback music / movies / series / whatever to the TV, and not be stuck with what they are offering on the hotel PayTV

for me, the convenience factor would be insane.

A composite or svideo out will just not cut it, as the picture quality is too poor to work with, this is what makes me unable to do the above with N900