For somebody new to the whole iTunes Store ecosystem it is neither faster nor less mentally challenging to set up a new ITS account than it is to jailbreak their new device.

It may strike you as obviously false, and it may well have been so two years ago, but when I got my new iPad after moving to another country I've spent about twice as much time getting iTunes to let me pay for apps in foreign App Store than I've spent researching jailbreak options and caveats and then actually pwning the device.

So no, App Store is far from the only way to distribute iOS software, even though it still is the default and sometimes the only apparent way.