If you drive the getaway car for a burglary, don't try telling the police they should let you off because it's a first offence. But if you are an agency that allows malware advertising, you need special treatment?
If the rules were in place - allow malware advertising and you will be suspended for a certain amount of time - the agencies would have to get their act together and perhaps adopt a system not so open to abuse. Of course this might lead to a lot less advertising. But that would possibly bring in more, not less, money, because fewer adverts means people more likely to read them, so the price you can charge goes up. Currently it's a Gresham's Law world with bad advertising driving out good; exactly the same as with any other currency. Serious regulation could be good for the more reputable parts of the industry, just as serious bank regulation (when we had it) gave people confidence in banks and so promoted trade.