The explanation from the central bank is Bitcoin and all other cryptocurrency are banned here because criminals use these currencies for money laundering and their crimes.
This is the lamest excuse the authorities and governments make when they want to ban or stop Bitcoin from spreading within the country because they know if that happens, they are slowly going to lose control over their people, their finances, and financial activities and they can't afford to let that happen. When they say that Bitcoin and cryptocurrencies are used by criminals to fund their crimes, they ignore the fact that criminals have been using fiat currencies for centuries for the same thing, but we never saw anyone saying that fiat currencies should be banned for this because they know it's them who are in total control of the money.
If they say that Bitcoin and cryptocurrencies are not traceable and that is the reason why they are against them and think they are easily usable for criminals, even cash that is used by criminals doesn't leave any traces for them to catch the criminals, if a criminal is using a specific currency for any crime, the money is then mixed in the economy and they can't find the criminals based on that.
There are not too many countries in the world that ban bitcoin anymore, most of them are starting to have a more positive view of bitcoin. So I think we should stop paying attention to what governments that are still hostile to bitcoin say about it. Sooner or later those countries will have to change their views on bitcoin if they don't want to fall behind the world. I'm still living in a country where bitcoin is still illegal but I'm optimistic about its future in my country. No country can stop the development of bitcoin unless they want to completely separate themselves from the rest of the world.