Sure making a phone call or sending out a message is all that you need to do in an emergency. But that's not what the cell phone is for anymore. Back when batteries lasted 3-4 days on a charge they were there for when you needed them. Now people feel like they need them all the time. This isn't a failure of hardware or software. A mobile phone isn't a just a phone anymore, so how can we expect it to have the same battery life as something that is just a phone?