nexus 4 propose ALL button in recent app page

i have a android phone nexus 4 and i have propose all button in recent app page, but killing apps is the worst thing you can do, the android system manages the ram usage for you!
i'm sad there are still people out there, who thing killing apps will give them longer battery life and apps are in memory, but are normally suspended (unless there are on-going functions, such as a music player). for android phone or android tablets the point of keeping them in memory is to allow you to quickly switch back and forth between them, rather than the lag of having to re-load the app. This is all part of Android's app management, and it does a great job of it. Closing those apps won't save much if any battery life, and Android closes apps automatically if it needs the memory for something else. Thus, there is little if anything to gain, and significant stuff to lose, by closing all of those apps all the time.

I do not like about that list is that it does not differentiate between an app that is still active and one that is totally dead. I have had a battery problem a couple of times due to apps running in the background without my knowledge.It's a good idea, why is everyone bashing the guy?! I support this cause never said anything about battery life, I'm the same way like many users, we close the apps we don't use or are done using so we can easily switch between the most frequently used ones
I'm running Paranoid Android 3.15. The app switcher button turns into a kill all button when pressed on this ROM. Forgot to mention it in my last comment. 2GB ram is overkill. Free ram doesn't help performance, letting apps stay cached for use later will. ike the Paranoid Android approach that above. Useful when I only want a few recent apps in the list for quick switching.