ENABLE automatic termination

I read that starting with Lion, when some apps have no open windows in the background, OS X automatically quits them. It's been working great in Mountain Lion, I liked it it TextEdit and Preview, especially. Now, in Mavericks, I noticed that this doesn't happen any more. When I close the last document in either one of the two, the app remains open even after I switch to some other app. I read in the Mac Developer Library the following:

Enabling Automatic Termination in Your App

Declaring support for automatic termination lets the system know that it should manage the actual termination of your app at appropriate times. An app has two ways to declare its support for automatic termination:

• Include the

  NSSupportsAutomaticTermination

  key (with the value

  YES

  ) in the app’s

  Info.plist

  file. This sets the app’s default support status.
• Use the

  NSProcessInfo

  class to declare support for automatic termination dynamically. Use this technique to change the default support of an app that includes the

  NSSupportsAutomaticTermination

  key in its

  Info.plist

  file.

There are no such lines in the plist of Preview or TextEdit. And I wouldn't dare to modify their Info.plist file... Or should I? Is there any way to get this feature back or to force its enabling? I know it should be there, by default, but it simply isn't. I tried repairing my permissions, restarting the system, but to no avail.

I am mainly interested in this behavior in Preview or TextEdit, but it would be nice to actually choose the apps that have automatic termination.

Thank you.