Yes it is used for some criminal activities but we should not care about it at all because this is life, the fact is that every currency has this down and dark side.
I do not care and I think its also logical and not so bad too.
Well bitcoin werent made for those purposes, dark or criminal activities, but sure each person does spend and use them as they wish, the same happens with fiat, its curious to see the media attacking bitcoin like the only currencie in the world supporting the dark marketplaces, something we do all know happens several years with fiat.