* Can't be blocked or monitored by state-controlled Internet

* Is widely installed throughout the population already

* Existence of which is not evidence of anti-government organizing.

That's what made AirDrop sharing so powerful for protestors. They all already had it, having it is not suspicious, and using it doesn't rely on government internet filters allowing it.

Apple isn't removing the only way to coordinate, but they are removing a mechanism which has reportedly been used by Chinese dissidents.