i do believe that one of the very reason why bitcoin become popular during its early stages was due to the support or usage obtained from criminal activitues.
We cant deny the fact that bitcoin has been by criminal since they have also seen the advantage of using it to conceal their transactions.
It would be naive to think criminal activity wasn't a major factor back in the day, but now most of the users of bitcoin are traders and users which want to earn money in a legal way, this is nothing new, a significant number of new technologies are adopted first by the military or by criminals so I don't think bitcoin is unique in that aspect but thank god we've left those years behind us.
Not only was Bitcoin used for criminal activity back in the day, but that was it's main use actually. Most online drug dealers, weapon sellers and other illegal activity providers would use BTC to accept payment for their services because it offered relative anonymity and ease compared to any other method that was easier for governments/authorities to trace.