I suspect that this is because iPhones are "cool" and someone high up just demanded that it should happen.
Targeting iPhone is like supporting a cable company's set top box, so highly prized because it's straightforward; whereas targeting Android is like supporting a myriad of smart TVs.
That's certainly true for supportability. It's easy to test and confirm that it works on the 2 or 3 iphone models, less so for all the Android devices. That's potentially bad from a PR point of view.
For drm-esque security it makes little difference though. The 'attack' in this case was from people running a script and pretending to be an iPhone, not from people running unauthorised software on iPhones themselves.