I can. E.g. my phone settings manager, my TV provider's remote app, my main screen of multiple widgets, my local TV station's weather app w/ notifications, etc. Also, in many cases for web apps w/ mobile app equivalents, the latter are easier to use and snappier. Finally, though less useful, this can give an app developer a sandbox in which to embed his app upon distribution and be able to target Android and Linux assuming the app is simple.
You'd be surprised. Android has full mouse and keyboard support - you can click on buttons, tab between text boxes, use scroll gestures... it's not perfect (and some apps are awful) but I've been very surprised by how much I can do.
https://infinum.co/the-capsized-eight/say-hello-to-a-faster-...
https://developer.android.com/studio/run/emulator.html
On my MacBook it's actually faster than the iOS simulator.
IMHO if this machine is linux, and that machine is linux, and both machines are fully open, then why can't you run this app on that machine? Because reasons, that's why... no more!
Also, Linux doesn't have many apps and small games. For example, if this works, Linux users can run Word and Excel, as well as Angry Birds.
In two years if there's no widespread adoption it will still crash because it's just another potential platform for QA to test on.
Also if I'm not mistaken it will only run apps that are compiled for x86 Android.
You might be able to work around that limitation by using an app like AppCloner [1] or Parallel Space [2].
[1] https://play.google.com/store/apps/details?id=com.applisto.a...
[2] https://play.google.com/store/apps/details?id=com.lbe.parall...