Whilst we have to wait for the official report, I dare suspect, like many others, that most if not all of the injured weren't wearing their seatbelts. Those injured while belted up were likely either only lightly injured and/or injured by flying debries, including unbelted passengers.
That said, I remember several long hual flights (7-13 hours) where the seatblet sign just seemed to be left on by default. Whilst the pilots obviously know more about the weather ahead than the passengers, the use of the sign did seem excessive to the turbulence present (at least compared to similar turbulance on other airlines). Airlines, possibly with a little firm assistance from civil aviation authorities, need to ensure that the sign is used properly. Of course, use it when turbluence is present, but don't expect hundreds of passengers to sit belted up for 10+ hours without being able to use the toilet just in case.
It is very common in any flight from or to China (or within), the Chinese nationals on the flight will all stand up and start to get their bags out of the overhead lockers before all wheels are on the tarmac - been there, seen it - is a commonly discussed issue.
Best effort I've seen at ignoring any sort of common sense was standing up the moment the rear wheels hit the tarmac on landing. Not even waiting for front wheel to come down. Needless to say there was a Great Wall between the passenger and a basic understanding of laws of motion.
I've seen plenty of this on flights to and from China and on domestic PRC flights too.
Chinese people don't. (in a generic sense) They contest and fight putting on seat belts in cars as well. In all the Chinese people I know, which is quite a few - only one is like us on seat belts - and the rest see them as a pointless accessory that infringes on their freedom.
Chinese people do not respect or even often know what a seat belt sign is for on a plane.
The obstacles may even be passengers who did the right thing and had their seat belt on. So people need to think about other people and not be selfish. You just need to put your seat belt on when seated, we do it in cars and don't give it a second though.
In China, apart from some taxi drivers who viewed my attempts to wear the seatbelt as some sort of insult, I have also been in several private vehicles where the owners have put in decoy seatbelt buckles so that the car doesn't make an alarm sound when someone sits in a seat without using a seatbelt.
That's before we even get to "driving" methods. Want to steal a march on the trafffic jam in front of you? Just pass the cars in front by driving on the footpath! If any uppity pedestrians dare to use the path for its intended purpose, just keep driving while blaring your horn at them. As long as you blow your horn, you can do whatever you want, it seems.
Try in the USA - often the seat belt sign is on for long periods when there is no apparent reason.
Many many PAX will simply ignore the sign after a while, generally to visit a lavatory. FA's don't seem to care.
To me this is a dangerous practice and should be cracked down upon. It's just crying wolf, as others have said. No point blaming the passengers for not wearing seatbelts if your pilots/company policy have been working their hardest to make the warning sign meaningless in the hours before the incident.
