It doesn't matter whether it is crap or not, whether it is true or BS, whether we like their opinion or not; Google should not be in the business of censoring sites, given its monopoly on advertising.
In that light, it is not the advertisers making the decision in this case. It is google refusing to place add for advertisers who presumably want to advertise on zerohedge.
Of course the above is simplistic. For one I don't know if alternative action existed that would not set a precedent of censorship.
It's really astonishing how much of a facade the commitment to free enterprise on the political right was now that some conspiracy websites get the treatment they deserve