I don't buy that (at least not for everything).
I realize that not everything centers around the malware issue, but if a site is distributing malware, why would you want to retain them?
Let's be honest. A site distributing malware shouldn't be allowed to advertise, but Google, whose company motto is "do no evil" is basically saying "Ok..you can distribute the malware as long as you pay us enough".
There motto and their actions seem in direct conflict here wouldn't you say?
I agree that the QS solution is likely a good solution for Google in many cases, but in this particular instance, it seems at odds with how they like to portray themselves.