If users use this in bad reasons then its possible but proclaiming that bitcoin is a criminal tool is a bit overwhelming since we dont know if its true or not. We need proof or evidence if that situation truly exists. With that we dont need to panic because as long as good users is more than the selfish ones then its next to impossible that bitcoin is a criminal tool.
Yes, I will agree with your conclusion, it depends upon the user of the bitcoin if He or She has a bad or good intentions of this cryptocurrencies. I think bitcoin is design for good reasons, but we can not also control those people who has a bad influences like terrorist, the criminals, drug syndicates and etc.They like to use bitcoin as payment to their transaction, because they can not easily monitored by our law inforcement agency.because bitcoin is decentralized.