This can change with the open web as software and services are moving to webapps and apis, BUT asically , Linux lacks of attractive software ,services and business providing services , for the public and businesses. And no , Open Office is not a replacement for MS office, nor Gimp can replace Photoshop for professionals.

Linux is not hard to learn, has great guis and works on most of the hardware.

There is potential but all the services are not there yet. Android is valuable because of all the service intergration it offers, not because it is *nix based , same with IOS.