Who says Apple is the only winner here?

To be honest, this is an overall gain for everybody involved with iOS. Developers who spend huge amounts of time coding and styling apps who just want a buck or two for their work are less likely to be pirated from, and thus more likely to keep coding and making those cool iOS apps. iOS users subsequently get more content from developers since the main source of app piracy (ie: Installous) is down. Apple benefits from the increase of good content.

As for the claim that jail breaking is gone as a whole with it? Well, there are plenty of other reasons to jail break other than pirating apps (like most cydia tweaks, Zephyr, Gridlock, etc.). We will probably see the community go down for good in a couple years, but only as we see Apple grow away from their simple sleek OS and embrace the huge amount of their users who want more options for their phones' and tablets' interfaces. Either that, or jailbreaking for iOS will stop because everybody interested in unrooted freedom will shift to platforms the encourage it, like Android.

Also, if people still want to steal their apps, there are still multiple ways to do so (Appcake, vShare, etc.)