All of them with corrupts goberments and state excess. They can't accept the idea of having a currency that the central bank can't control.
Some are just afraid, or confused.
India banned bitcoin when they found out government officials were taking bribes in cryptocurrencies.
China first banned bitcoin because people were using it to transfer money out of the country, as sending large amounts of money abroad, or leaving China with a lot of cash is prohibited.
Some Muslim countries ban it because they think investing is gambling and that's against their religion.
These are some examples of hos corrupt governments are trying to rule with an iron fist.