I have never heard anyone say that
And it's foolish
Anyone who says "doing drugs is not a victimless crime" is implying exactly that; that drug users are victimizers. Words have meanings.
Of course, the logic is ludicrous. People can do drugs and hurt absolutely no one. Doing drugs is a victimless crime. The drugs get blamed for people's violence and irresponsibility, just like guns get blamed for violence and irresponsibility. Owning a gun is a victimless crime, too.
Its ridiculous to punish people who mind their own business, with drugs or guns.