I'm just not packing a desktop monitor in my hold luggage, it would get trashed. Maybe not the first time, but theres no way it would survive multiple trips.
Tablets are fine for maybe loading a couple of movies on, or light email, but they aren't a replacement for a full laptop. As I also said already, its not just the plane, there are plenty of situations where I don't have the time or space to set up a full desktop rig so I would need a laptop with me on trips anyway. A GPU takes up little additional space, its not at all practical to pack a full desktop setup, regardless of how small the PC itself is.
I don't know how often you fly, or in what section, but I see plenty of other people with laptops.
The sentiment in this thread seems to be that no one in the world uses a laptop, but we know that's not true - and for anyone that wants a low power laptop with the OPTION to plug in a more powerful GPU when time and space allows. Its a niche yes, but so is SFF.
And yes, I have even been to a gaming convention and seen competitors using laptops, so saying "oh they just all take SFF PC's" is not even true. If anything I would say the moba guys mostly had laptops, and the FPS guys had full desktops, I saw hardly any SFF's being used.