I still can't wrap my head around, why they used Android 4.4 instead of just using linux, this does not seem like a new paradigm, just a minor "innovation".
2) If you're someone like me who drops in to distrowatch.com occasionally, you might think a tweaked version of Puppy or Tiny Core would be more appropriate for older computers. And you'd be right in terms of hardware requirements, but...
3) Android is supported by Skynet, er, Google with massive resources. The installed base in the US is north of 80M and it has support for 47 languages.
So it's really the answer to that classic question, "what's the simplest thing that could possibly work?" If I were in the project manager's shoes Android would be at the top of my list as well.