[dozzie]

> You can replace NT with Linux (or Linux with NT) as well.

No, not quite, not without enormous effort. Look at Cygwin or WSL or Wine: tons of work poured into and still not there yet.

On the other hand, typical Android application only ever touches Android's API and doesn't even leave its JVM. Replacing whole kernel (with obvious single point of work in Java interpreter) would be practically invisible.