Maybe there are some people love to use bitcoin for illegal activities it doesn't mean bitcoin is responsible for that. Bad guys also can use fiat currency for an illegal purpose.this is one the reason for banning bitcoin in many countries but in reality, bitcoin is the source for making development.
Terrorists do not always use crypto money to finance their activities, because of terrorist financial sources from various sources. One of them is interbank transfers disguised in business transactions using accounts of companies that have legal businesses. Or manage a company where profits are obtained for terrorist operations. Crypto money is only one of them.