Comment by wilsynet

Because that would violate the Apple rules (and also be practically infeasible for technical reasons).

You can officially (as a matter of policy and enforced by iOS) distribute apps in 3 ways:

1. Through the App Store

2. As an enterprise developer distributing apps to employees of the same company through an enterprise App Store to an enterprise enrolled iOS device

3. As a developer to a test device where the test device is 1 out of 100 registered devices in your Apple developer account

The only other alternative I'm aware of is to jailbreak the device and distribute via Cydia.