That may be part of the intention but they surely aren't going to get the level of bug reports without a subset of users outside of the dev community. Again we are talking about APPLE, the company with hundreds of billions in cash.
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Maybe so but how is battery performance something that needs to be re-learned on every friggin new version of the OS? You'd think they know that is 1. A priority and 2. Something that they've optimized on every previous version of the OS. 3. How does a beta even go out without having battery life optimized from day one?
Three years ago Apple said that allowing apps to run in the background was terrible on battery life. This hasn't changed, but Apple went ahead and allowed users to pick whether or not to have the new feature since Android had it. Want to save battery? Turn off Siri lift to face, disable Background App Refresh, and pay attention to how often GPS is flicking on for your phone. I've noticed location services runs far more often and that turning on requires the GPS antenna to be on. GPS is comparatively a huge power draw. While this won't return you to iOS 6 level of battery life (Your phone does more now. Those new features aren't free in terms of CPU and GPU usage), it will help some.