are you late to read the news ? I think China has been doing it a few months ago. nothing happens excessively, just look at the current bitcoin without china, india and russia. bitcoin instead goes up without hesitation.
I think you need to read the news again. China has not banned bitcoin. China has banned bitcoin exchanges from operating in their country. There was no ban on mining, no ban on buying bitcoin (because you can buy from any exchange in the world), no ban on holding bitcoin, and no ban on transacting bitcoin with others!
Bitcoin should be banned!
Why?