But if the service is legit as it seems to be, allegedly does a lot of good to Bitcoin as well as attracts a lot of new users into it, would banning it do more harm than good in the long run even if the majority of their posters are posting pure crap?
In this way, punishing the service itself looks counterproductive, but I seem to repeat myself
That's like the primary reason for which the campaigns are not completely banned. They let newbies earn a little, and provide bonuses to people that truly contribute. That said, whether a service is useful or not is irrelevant. Rules are rules and should be applied to all as equally as possible. That said, Bitmixer is a bad centralized service that will get replaced by Joinmarket anyway. They should be the first one to be completely blacklisted.
Read the post from hilarious. Also: This spam causes a lot more damage than good. Quality members are either completely ignoring certain sections or jumping the ship.