They believed that this decision made was as a result of being the use of cryptocurrency as a means to engage into illegal financial activities such as scam and other fraudulent attempts by the people, you can read further from the links below and drop your opinion on this ban.
When almost all parts of Subsahara Africa are friendly with bitcoin, those North Africans which are Muslims against it. It got better over time but now Algeria is making things worse for their citizens because of their government self-centeredness. I will say the reason you stated above can be what their government said but the main reason they ban cryptocurrencies is because of their ignorance and their illiteracy part of themselves.
I cant completely tag a whole nation as fools and that they lack the knowledge of bitcoin and it usefulness in a growing economy. they might know about bitcoin and it usefulness but can at the same time be drawn to a point where they get short of options other than regulating how it is being used in their nation. in most civilized nations, it is hard to find cases of abuse of bitcoin as much as it is found in most African country and just like what is happening in Nigeria, the regulation against crypto is not just because the government hates it, it is because some unfortunate minority have decided to use it to carry out some negative things.
of cause not all countries will be positive about bitcoin, some will be agsint it but even with that, bitcoin will continue to do better.