Bitcoin was primarily used for underground purposes but it's moving away from that. The internet was arguably just used for underground activities at first and criminals took advantage of it as well like they do with any new technology, but any good idea will outgrow itself eventually when others realize it.
the fact that bitcoin is and was used for underground and illegal purposes is something inevitable, but to say that its primary purpose is for criminal acts is completely off the mark.
everything is being abuse but to say the that thing is only for abusing purposes is short sighted.