miners in china and the china bitcoin ban

it never added up in my mind how come there is a bitcoin ban in china and yet most of the world's mining operations are going on there, every once in a while there is an article about one crackdown or another from china when it comes to bitcoin, but as far as blockchain is concerned, their approach is even favorable, there seems to be no reasoning behind this and yet things like this go on uninterrupted

https://www.coindesk.com/chinese-region-to-shut-down-illegal-bitcoin-miners-by-september/