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.

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.

And since we're being pedantic here, let's talk about definitions. A mobile operating system is one that has been designed primarily for devices intended to be carried on one's person, such as a phone or tablet. A desktop operating system is one that has been designed primarily for devices that are large enough to be stationary during use (e.g., workstations). Both form factors have unique requirements and capabilities, and need vastly different user interfaces.

Further, you seem to be arguing that the kernel (and only the kernel) is what defines an operating system. If that's the case, then Android can only properly be described as a fork of Linux, not Linux itself.

And one of Android's original use models was a non touch screen connected to a keyboard (mainly for Blackberry style smartphones before they were sure that slates would take off, but still...).

Of course I use it mostly to play around and do tests.