And no, you can't build this stuff in userland. Everybody could go install Cyanogen on their handset, but that's obviously not tenable for the general consumer.
This is a puzzling concept. If there's a need for a product, it would've already been created? By that definition, we should just shut down HN, since there is no more need for startups! Why waste our time here when every piece of software with significant demand has already been written by somebody else?
Goofing around aside, there is a lot of Ameri-centricity in both iOS and Android. For one thing, I cannot believe Apple is shipping the iPhone in Japan without a QR code reader.
The whole "translate it and ship it" attitude to globalizing products is a poor one, and explains why some scrappy locals can often take on big, cash-flush corporations.
The point of Android is to sell search ads. So I don't think they want Android to be relevant anywhere but "the West". If you want to use Android and have it support your obscure legacy technology, bust out your IDE and start programming. If there is as much demand as you say, the money will flow right in.