They are not totally greedy since they do know their own capability when it comes to money and i do strongly believe that this actions had been made is purely concerened on protecting its citizens and at the same time they dont like for their money or finances would really be putted into another indsutry this is why they do decide such blockage but one things assured on where no matter how they do oppose cryptomarket it will stood strong.
The Chinese government ONLY cares about itself, and not about what its people do. If they really cared about their people, even if it is just a little bit, they would allow everyone to enjoy far more freedom than is the case right now.
I'm living in a civilized country with at least a decent form of financial possibilities, which means that if I so wish, I can transfer all my wealth to another country without any problems.
Everything you say about China that it wants to protect its citizens, can basically be applied to any other country, which by your logic would somewhat justify banning everything they deem to be a potential threat.
Japan is a great example when it comes to exposing how bad China actually is when it comes to allowing its citizens to enjoy more overall freedom. The Chinese government knows that it's just a muppet show.
It's not for nothing that people want to park their wealth in a different country, think about that.