Chinese Central Bank gave many reason for developing their own cryptocurrency like lower operating costs, greater efficiency, and better control of illicit money flows. But what I believe is that they are bringing their own cryptocurrency because of the increasing popularity of bitcoin. It is like if you can't beat them, join them.
What they do not understand is that attitude will legitimize bitcoin even more in the eyes of the people and investors, since they will see bitcoin is way better than this crypto created by the Chinese simply because it was not created and controlled by any government, so in a way in their attempt to try to discourage bitcoin adoption are only going to help bitcoin even more.