Thus, previously, users in China could set their phone to be able to receive airdrops from anybody, all the time.
But, problem! Now they can receive information antithetical to CCP propaganda, anywhere they go. On a bus, on a train, at the supermarket, at a grocery store, literally anywhere, they could be exposed to ad-hoc free thought via airdrop. Perhaps something like: "protest tonight at the grocery store! They can't arrest all of us!"
In response, now iPhone users in China can still choose to receive airdrops from anybody, preserving the valid use case, but only for 10 minutes after pressing the button. They are now safe from uncensored information for the rest of the day. Train, bus, supermarket, etc. The airdrop protest invite is now dead.
A complete ban of receiving airdrops from anyone would cause outrage - it would be removing a useful feature entirely. But the timer is a clever way to neuter its position as a social communication platform without taking the useful feature away.
This is how effective social control works - you can't just shackle everyone, you have to give them the impression of freedom.
Before state: some of them have airdrop set to open always and you can just airdrop to them. Move on to the next bus.
New state: some of them may have had airdrop set to open always, but it timed out. You cannot airdrop it to them. Protest quashed.
I'm still telling the same story but perhaps this makes the mechanism more obvious to you. The fact that you genuinely don't seem to see the censorship shows how effective this strategy is.
I can see how this limit would make free data exchange much more difficult. I am still not convinced that by this protests are “quashed”. We’ll see about that I guess.
That pretty much kills Airdrop as an open P2P communication channel (the "undesired" usage) while still enabling one off intentional file transfers (the primary Airdrop use case).
So a 10 minute limit easily kills 99% of "bad" usage without impacting common usage, leading to less resistance/complaints from average users. Killing Airdrop full stop would have greater push back/outrage, with only marginal improvement against the undesired usage.
Q: How does 10 min limit kill the P2P communciation usage?
A: Imagine your cell phone could only receive calls from non-contacts for 10 min. After which you had to remember to push a button to re-allow calls for another 10m, rinse/repeat. With that UX, the chance you ever successfully call or be called by a non-contact is near zero. People wouldn't opt-in frequently enough to have a reliable network.