Accepting new things or technology or method is always difficult. It takes some time to understand and then take a decision considering the pros and cons of that thing. On an individual basis, it's little easier and a quick process to accept any new thing. But if the decision is required on the government level it's difficult to take a quick decision it takes time. Because many things are connected with other government official have to check all that.
Iran government take its time to analyze the crypto or bitcoin mining. After considering its pros and cons their final decision is to accept Bitcoin mining as an industry and setting electricity tariffs to mining Bitcoin in Iran.
It's cheaper to mine Bitcoin in Iran because its electricity tariff is low than in other countries. Approx $0.06 cost per kWh in Iran and in developed countries its approx $0.20 per kWh. New proposed price to mine crypto in Iran is $0.07 per kWh. Its the cost just for the miner who wants to mine crypto. According to an estimate, there are 148,000 mining machines crypto in Iran.