I'm in way too late on this thread for this comment to be noticed, but this is so absolutely self-serving for Apple. DO NOT LAUD APPLE FOR THIS.
If Apple were doing this for any reasonable purpose, they'd do it on Safari on the desktop as well. Almost every sane reason for blocking ads is as pertinent there.
They are simply trying to force content providers to go native app and become part of the Apple revenue stream. That's it, pure and simple.