To be clear, the parties behind these sham recovery centers are scum that deserve any and every legal repercussion available. And, if illegal, no Google shouldn't do business with them. But the bottom line reason why Google didn't act faster was because they weren't per se illegal, but more so loophole exploiters.
Policy makers subsidized an industry and, learning nothing from every other subsidy in the history of the world, forgot that subsidies invite bad actors. (Calling coverage of medical treatment a 'subsidy' is admittedly somewhat of a stretch, but in the context of all the medical issues that health insurance does not cover I stand by the label. E.g., German public health insurance used to cover 'prescriptions' for sun and relaxation, until it became abused by people taking taxpayer subsidized vacations. Designations of coverage have a similar effect as a subsidy, at the very least.)
This path we're heading down of expecting "the internet" to protect us from the latest baddies out there worries me on a much deeper level. And I don't see this as a 'slippery slope' argument: this is just looking at existing data points and following the trajectory. The current direction is worrying, without regard for the potential of acceleration. Exploitive ads have been around forever -- from the literal snake oil salesmen to the ads in every newspaper, magazine and yellow pages to the present.
Hard cases make bad law. That's a maxim that is depressingly unpopular today.