I realise few people here believe there's a world outside the Anglosphere, but...
...you'd be surprised at the market share of the Lumias (and other Windows devices) in the non-English-speaking world. Windows-based phones own about 10% of the Italian market, for example. (Then again, Italians seem to be rather better educated on privacy issues too.)
Android has its pros and cons, but privacy isn't something one tends to associate with Google. Localisation also tends to be very hit and miss, especially for the custom skins / launchers. Microsoft, on the other hand, do localisation very well. They're also pretty good at privacy, even if you do sometimes have to dig down into the Settings app to disable some of the "newbie-friendly" features.
As for the app situation: every Universal Windows 10 app supports ARM, and there are already more of them than there are Windows (Phone) 8 apps. If your app isn't there, there's always SSH or the remote desktop option. And Continuum means you can do the latter on a larger display.
Also, a little basic research would show that Continuum can be used entirely wirelessly, using Bluetooth mice, keyboards, and a compatible HDTV (which is pretty much any TV with the word "Smart" on the packaging). The "Desktop Kit" -- or anything like it -- is therefore not required.
Most users of the feature are unlikely to be attempting to write a novel or 300-page report on the thing anyway. As someone who's had to wear glasses since I was six, not having to squint at a recreation of a hi-resolution desktop on a 6" display is a *very* useful feature. Not all of us IT folk have perfect vision.
This is very much a v1.0, but it'll be interesting to see if the rumoured "Surface Phone" comes with an Intel CPU. If it does, and they've smoothed off Continuum's likely rough edges, I suspect it's going to do quite well. (It'll also be interesting to see how well it handles gaming, though lag may be an issue if using Miracast for the display.)