I agree that there is a problem, but I think that this time around it is a smaller percentage that are having the battery drain problem associated with iOS 6.1.3 I have an iPhone 4S, 32 GB, AT&T and had battery drain problems with one of the iOS 5.X updates. I did the battery discharge and full recharge, reset all settings, and have always used fetch rather than push email.
With the iOS 6.X updates, I have had very good to excellent battery life, iOS 6.1.1 did seem to have a higher than average battery drain (FOR ME) than I had seen in the others. 6.1.3 seems to be fine as far as the battery goes for me as well.
The one thing I have noticed in my very unscientific study of this problem is that the majority of people who have this problem did an over the air update, or backed up to iCloud.
I would recommend that you do your updates through iTunes, before you do the update, kill all the apps running in the background, reset the phone so that it is in a clean state (as far as memory goes) and then reset it again after it updates and you have completed your restore from your backup. Then run the battery all the way down to dead and charge it over night. This will reset the battery counter, which actually seems to be part of the problem.
I am not saying that there is not a problem with the OS and that this has to be frustrating for those that have it. I am just saying that this has worked for me and I have really good battery life for a smartphone in general. The screen draws a lot of juice, just using it to surf the web uses the battery a lot, if you use push email for work, that will also use a lot of battery. Once they finally develop a battery that holds a lot more charge than we are seeing today this might get better, But for now smartphones, Apple's as well as all the others will continue to chew through batteries like they are going out of style because they are doing so much with a tiny battery. Or we can go back to big bulky phones that have nice big batteries. The technology will eventually catch up. Until then we sadly need to either carry a backup battery/charger or not use all the cool features that we have been promised on our phones.
I am looking forward to Google finally making Google Now available to iPhone and I am sure it will eat my battery alive because it will need to use location services which means GPS.