[fpgeek]

There is this thing called the Amazon Appstore. Perhaps you've heard of it? On anything but an official Amazon device, it works entirely by sideloading [1]. And considering the broad impact this particular use (not to mention other important ones) has had (e.g. Amazon's official devices probably wouldn't exist without their use of sideloading to bootstrap the app ecosystem), saying sideloading primarily used for piracy is just wrong.

[1] Ironically, I think the pervasive sideloading third-party app stores on Android require is a bug, not a feature. I'd much rather see an official way to add "known sources" so that, after the initial install, you didn't need to leave sideloading enabled in order to use them.