Bitcoin will be used for good as well bad things the same way it happens for several years with fiat, soo nothing new here, besides its harder to trace the people who are under the dark marketplaces.
Indeed you are right but I think its logical because every currency is used for some criminal activity these days and we can do nothing about it too.
I think its logical and not bad that it is used for it because we cannot do anything about it, it may even give the bitcoin a boost.
That is already on the decision of a certain user, if bitcoins are used for illegal activities a smart investors would understand that it is just normal for every currency and in fact when it is used it could already help the economy of bitcoin to prosper as the circulation is good, we should just invest instead.
Correct it depends on the individuals and i think it is much convincing & safe transaction for illegal users because bitcoin can not required more information of all users before to have bitcoin wallet. We do not please not to do the illegal transaction because it is their decision and wants.