A cell phone, by design, is a portable and mobile device. The cell phone marches on the strength of its battery. Because of this, it is much more important for a maker of the devices to equip them with stronger and better lasting batteries so the phone can perform while on the road.
Updating can wait until the phone is plugged in and charging as updating is not as important has having a phone that can make/receive an important call or SMS, or make an emergency 911 call. It is logical to conclude that apps should always be secondary to the primary "lifeline" function of a cell phone.
The reduction of battery power usage should bring about a parallel reduction in the amount of charging for phones. When one considers the vast numbers of mobile phones in the world, this must represent a good thing in terms of the amount of electricity used in the world. It may be a small step, but it is, at least, a step in the right direction.
I have no qualms with manually updating the applications on my cell phone, but the most irritating thing about my iPhone is how often the battery dies. I have to keep a phone charger with me in order to maintain battery life. I think it's far more important for cell phone manufacturers to focus on battery life than continually updating programs.