What exactly is a logical difference in this case, and how is it relevant to the discussion? Is my decision illogical if I consider the ergonomic implications of using a particular hardware/software platform?
Aside from ergonomics, I'm not sure what is so controversial about assuming that the different user interfaces will (and quite obviously do) cater to different use cases. What I can realistically do with a keyboard and a 24" monitor is certainly different from what I can do with my mobile phone. What I can realistically do with Debian is certainly different from what I can do with iOS or Android. These differences alone convince me that the distinction between desktop computer and phone/tablet/crablet is still meaningful, regardless of the literal meaning of "desktop computer". Manufacturers, retailers and consumers generally understand this, no matter how much anyone pretends that a tablet is equivalent to a desktop computer.
> "year of Linux on the desktop" People have been using [insert any relatively obscure OS] as a desktop OS for plenty of years. The fact remains that Linux doesn't hold a significant share of the desktop market, which is what the idea of "year of Linux on the desktop" has always been about.
You can use a smartphone with a bluetooth keyboard to write business docs with wordprocessing apps or construct spreadsheets (you could use the on-screen keyboard if you're a masochist). Different physical interfaces target different use cases as we've both noted but the distinction is more about marketing than ability of a system.
Going back to where this all came from I doubt this discussion is fruitful.
I think the point here is that "desktop" as a location has no real meaning - it's the use case that defines it rely. By desktop system one really means a day-to-day used system that is used for word-processing, web browsing and other standard domestic/work uses (photo editing, spreadsheets, games and such). That's the stuff a desktop system has always done and now you can do that on a phone, phablet, tablet, laptop, desktop or whatever. The hardware form is just about convenience it [no longer] describes a logical difference or significant processing ability [eg my phone has about as much processing power as my desktop (ignoring the GPU), some phones definitely have more]
If you're using your phablet paired with a keyboard for the same uses as others use their [traditionally defined] desktop for then what use is the distinction?
Android can be used on the desktop, but IMO it's not tailored for that and so shouldn't be described as a desktop OS.
The whole "year of Linux on the desktop" thing is about market-share as much as anything; as other have said many people have been using it as a desktop OS for plenty of years.