As far as I understand, only black-listed tags cannot be used, so e.g. this tag was an option to choose. I assume that the (new) user also might have decided if 600 members follow this tag (and currently 2k questions), it might be well chosen.
So my question is: Is there an option to unsubcribe all users using these cleared tags because atm they are unuseful? If it is possible but not found as a real option, what might be the reason?